+- STD (https://www.superturbodiesel.com/std)
+-- Forum: Other (https://www.superturbodiesel.com/std/forumdisplay.php?fid=19)
+--- Forum: Open (https://www.superturbodiesel.com/std/forumdisplay.php?fid=13)
+--- Thread: Diagnosing overheating and no get-up-and-go (/showthread.php?tid=3847)
Diagnosing overheating and no get-up-and-go - JustPassinThru - 08-15-2012
Hi y'all,
I'm having to diagnose my 1985 300D.
Two weeks ago, it started to overheat, and when it touched 120 C I pulled off the road and had it towed home --Triple A is a Good Thing. Dismounted the radiator, straightened all fins, installed the Prestone tee between the block and the heater hose, removed the thermostat, reinstalled the radiator, flushed the system with a garden hose, including with the engine running for 5 minutes. I did not see any significant amount of junk or crud in the flush water. Right now the system is filled with water and Prestone flush, no thermostat. I can drive it about ten miles before the temp needle crosses 100 C.
Meanwhile, during the two weeks the car was up on ramps...I did a valve adjustment (they were not too far off). Since I had the air cleaner off, I took the opportunity to unscrew the banjo bolt at the rear of the intake manifold, and sprayed it out with carb cleaner. The bolt was gunky but not totally clogged. The small plastic pipe (which leads to the ALDA via the overboost protection solenoid valve), when I tried to work it off the banjo bolt's barb, snapped off, so I've had to reconnect it using a short length of aquarium tubing. And I have a boost gage tee'd in, tucked under the wiper blade on the driver's side so I can monitor boost whilst on the road.
Now the car has no get-up-and-go.
Since I've been running 87% WVO for about 25,000 miles, I began to wonder if I've somehow ruined my turbocharger (e.g., stuck wastegate). This is the stock Garrett T3. So I checked boost under various conditions, with these results:
Car in Park:
idle: no boost.
revving: about 5-6 psi at 4,000 RPM
Car in Drive, flooring the pedal:
2000 RPM gives 4 psi at 25 MPH
2500 RPM gives 9 psi at 50 MPH
2700 RPM gives 9 psi at 60 MPH
Car in Drive, steady speed:
2 psi at 50 MPH.
Before I proceed to test the boost sensor on the manifold, and the overboost protection solenoid valve, and the ALDA, I'd like experienced opinion, as to whether the above boost values seem reasonable. About a year ago, I did have a boost gage on the dash, and if memory serves these were about the same values I saw a year ago. But perhaps I'm mistaken.
Also, does anyone have opinion, of whether the scenario of, first it overheats, and then it loses get-up-and-go, is suggestive of the failure of any specific component?
I did take it for a 2-mile test drive with the air filter off; it made no difference.
Thanks muchly for any help.
Update, a little bit later: I have now tried running a plastic tube directly from the intake manifold's banjo bolt to the ALDA, with a boost gage tee'd in. No change in boost values under various conditions, no change in the sluggish performance. But at least I have eliminated the intake manifold's boost sensor and the overboost protection solenoid valve as suspects.
Hard to believe an ALDA can just fail suddenly like this.
Hmmm...methinks next I'll try a diesel purge then fuel filters change...
RE: Diagnosing overheating and no get-up-and-go - Greazzer - 08-15-2012
Overheats and no get-up-and go ? Story of my life ? Old agie ? LOL.
I would double check your valve job. Sounds like the clutchfan could have went. However, after 20 mph, ram air will beat any fan out there. Timing could do this. Even with the banjo bolt totally pluggd up on the manifold would not cause this. Mine was plugged up before I cleaned it out and nothing like your symptoms.
RE: Diagnosing overheating and no get-up-and-go - Hercules - 08-15-2012
Need the thermostat In for proper cooling,slows water flow through radiator to give time to cool off. Install new German type,
( Behr,whaler,)etc,installed properly . Radiator should be psychical cleaned on inside(rodded out) ,usually radiator shop will
hot tank,and than remove one end of radiator,cleaning tubes with tight fitting rods, pushed down each tube removing deposits.
Shop must install new top tank,because of known breakage of inlet pipe,(do they know?).Many radiator shops use worn push rods,(they wear quickly )poor cooling results. If radiator more than 7yrs old with average usage,10-15 thousand mi yr. Time for New radiator. NOTE; Is water being lost. Also must have good radiator cap.
Exhaust mufflers can become restrictive , drop off head pipe to ck.
Low power,is egr still connected? Is egr stuck open? Ck; with engine at normal temp. engine off, pull vac. on egr than remove vac.quickly listen for valve to Snap shut.
Be sure to ck throttle linkages for full engagement. Good Luck.
RE: Diagnosing overheating and no get-up-and-go - larsalan - 08-15-2012
Maybe silly to ask. But if you are putting all that grease in the tank maybe there is a fuel problem somewhere between the tank screen and the injectors
? Like you said filters maybe slowing fuel.I think that 'diesel purge' stuff is a waste of $. I mean if your putting wvo in your tank then you'll just be gumming the delivery system up again anyway.
Oh and the 'diesel purge' is like 98% naphtha, so why not just get a gallon of naphtha?
You see what that temp needle does once you add some ethylene glycol.
Is the level on the coolant changing at all?
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 08-15-2012
Thanks hugely for the advice so far.
I did the diesel purge and changed the filters; the pre-filter (small straight inline one) was heavily clogged with debris. Not soot, not tar, not fat, mostly looked like rust particles. I'm guessing that the solvents in my fuel mix are giving the fuel tank a good cleaning.
During the diesel purge, the engine regained some, but not all, of its ability to rev up quickly. And but, it lost the sewing-machine-like ultra-smooth idle I have been enjoying ever since installing new injectors about 25,000 miles ago. Now it "lopes" a little like all the other ones I've ever seen do. I presume this points to a blockage in a line and/or a problem in one or more of the injectors.
After the diesel purge, it has regained some power between 40 and 60 MPH but is still very slow off the line. Though, slightly better than before.
Also, I just noticed this, I've lost my transmission kickdown. Have to shift it manually to downshift for acceleration. Hmm...both the ALDA and the tranny are connected to that blue flying saucer thing-y on the driver's-side fender...wonder what that is...
The diesel-purge-and-filters-change appears to have somewhat mitigated the overheating problem. If I can keep it between 40 and 55 MPH, on the level, even on today which is an 85 F day, the temp gage stays at or below 100.
So I will heed Hercules' advice --many thanks, I didn't think of that-- and, as soon as it cools down, install the new thermostat I just bought from the MB dealer. Brand is not shown anywhere, but the packaging says it's part A 617 200 18 15, Made in Germany, and it has 002 203 7575 stamped on the disk. The Mercedes tri-star is also stamped on the disk. The letters "BTI/BTO" are stamped on the front-facing part of the frame. It's an 80 C thermostat. Also I'll add a bottle of Water Wetter to the coolant water and see if that has any effect, during the 3-to-6 hours the label says to drive with the Prestone Flush + just plain water in the system.
Rodding it out must be terribly expensive. I imagine in the long run it's cheaper just to buy a new radiator. Let's see if just a flush will bring the temps down.
The coolant overflow reservoir cap is nearly new, good rubber. There is no evidence of leakage --no drops, no hissing. Water level is remaining at the spec line in the reservoir. I am aware that water is a better heat removal medium than ethylene glycol.
It will be a few days before I can drop the head pipe and run a snake through my exhaust system. I'm scheduled to work the next three days, so may be a week before I get around to it.
I should probably tell y'all what I'm burning as fuel. It is not straight WVO. It's the Diesel Secret Energy formula plus a few added ingredients. In a five-gallon bucket I mix:
4 gallons extremely clean, water-free canola oil
1500 ml JP5 aviation grade kerosene
750 ml regular unleaded gasoline, Chevron or Shell.
230 ml Diesel Kleen, gray bottle (twice the dose recommended by DSE)
18 ml Diesel Secret Energy proprietary Alternative Diesel Fuel Additive
and then I add my own recipe, of
50 ml turpentine
34 ml Marvel Mystery Oil
34 ml Red Line SL-1 injector cleaner
10 ml StarTron enzymatic Diesel Additive
5 ml acetone
It is thicker than diesel, but not nearly so thick as straight vegetable oil. Up til now, the car has for about 25,000 miles been running spectacularly well on this. I have a 120 mile commute, average a four-day work-week, so burn about two tankfuls a week.
Hmmm... the EGR now passes the MityVac-release snapback test... *however* the *first* time I tried it, the hose broke at the EGR's nipple *without* vacuum then being applied and *at that moment* I heard it snap back. Which is to say, it was *stuck open*.
In an hour or so, I'll take it for a test drive. ARV vac line is blocked with a golf tee. So now is the EGR. So are the other sides of the vacuum lines leading to the ARV and EGR.
RE: Diagnosing overheating and no get-up-and-go - larsalan - 08-15-2012
I would pass on the
turpentine too gummy
acetone too solventy
gasoline too solventy
that other stuff sounds like fine fuel
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 08-15-2012
I have found that turpentine with a little bit of acetone, is a good solvent for polymerized canola oil, which would be the main "gummy" thing which the use of WVO would entail. Also, turpentine is said to raise cetane level slightly. However, any more than 15 ml acetone per 4 gallons, causes the idle to become rougher. So I play it safe and add just 5 ml. I've also tried raising the amount of turpentine, but beyond 50 ml saw no benefit.
Gasoline "too solvent-y"? I've seen ForcedInduction, before he was banned, write here that one should never put gasoline through a diesel engine, but I have also read that adding gasoline for winter thinning of diesel is recommended *by Mercedes-Benz itself* --so, who's right?
The WVO-kero-gasoline-Diesel Kleen-DSE additive, in the proportions I give above, is the DSE formula --except, I double the dose of Diesel Kleen. The DSE website has umpteen testimonials stating that it works. I do notice, however, that none of those testimonials involves any engine newer than about 2005-2006.
It certainly has worked well for me. Until now.
Road test, in about two hours. I'm dead sleepy, got to catch 40 winks first.
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 08-15-2012
Road test: still has no get-up-and-go at the low end; barely adequate 40-60. Temperature stayed at all times below 105 C, even though air temp has actually *risen* this evening, it's now 88 F out. Presumably the improvement in cooling is due to the Water Wetter. So I guess I have a car to go to work in, tomorrow morning. Back in a few days, to report the results of pulling the injectors and I guess adjusting the ALDA. I'm beginning to suspect that I have just witnessed the death of my ALDA. Unless that flying-saucer thing-y is somehow contributing to the mischief.
RE: Diagnosing overheating and no get-up-and-go - Hercules - 08-16-2012
Sounds like the injectors got sticky when engine over heated. When checking exhaust just unbolt head pipe ,move aside,making sure pipe is still secure. Short test drive should tell all.
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 08-27-2012
Update, 11 days later. I have not had enough free time to disconnect the exhaust system, nor pull the injectors. All I've done is drive the car about 600 miles, mostly on the freeway. Tonight, quite suddenly, it regained its normal get-up-and-go.
I'm guessing that, as the temp gage edged up toward 120 C, the heat must have loosened some gunk in the IP and/or the spin-on fuel filter, which then partially clogged one-or-more injector lines and/or nozzles. And that, whatever the gunk was, simply continuing to drive it 600 miles at 60 MPH resulted in the gunk getting dissolved away. I did raise the turpentine in my latest 10-gallon fuel batch (it took 10 gallons to fill it up) from 50 ml to 100 ml, and raised the acetone from 5 ml to 10 ml, per every 4 gallons of veggie oil.
Still doesn't have that silky-smooth idle anymore, though.
Just running a bottle of Prestone Cleaner (I mistakenly referred to it above as Flush, but no, it's the more aggressive Cleaner product) through the cooling system, seems to have taken care of the overheating. With 50-50 water and Zerex G-05, and Water Wetter, it's reaching 95 now only on long uphill freeway stretches, or long uphill grades in stop-and-go rush-hour traffic in 85-degree weather. Usually hanging around 80-85 now.
So I guess I've been lucky.
RE: Diagnosing overheating and no get-up-and-go - willbhere4u - 08-27-2012
Also check that little u line that bolts to the water pump and the engine block and then the impeller blade on the water pump. both of these can sporadic cause overheating issues!
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 08-29-2012
What is the u line's function, and what am I looking for, both on it and the impeller blades (aside from, obviously, eroded blades)?
The flush water from my coolant system had a great deal of blackness in it. Fine stuff, like greasy soot. No chunks.
Next thing I'll do, but this may not happen for awhile, will be to pull the injectors and see what's going on, in both the injectors and the lines. I'd really like to get that smooth idle back.
RE: Diagnosing overheating and no get-up-and-go - sassparilla_kid - 08-29-2012
Scroll about halfway down the page, and you will see what to look for with the little breather. I never thought about it either until I read Captain's thread a while back
http://www.superturbodiesel.com/std/thread-1479-page-3.html
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-20-2012
The little breather, it turns out, does not exist after 1981 (EDITED: nope, incorrect, see posts 16 and 17 below).
But, the water pump has turned out to be the culprit...I think. The car started overheating again yesterday, but luckily I saw the temp gauge spike and had it towed home again; this time, the water pump is definitely rattling. Which seems a bit strange as there is no leakage and, grabbing the pulley with the fan off and trying to shake it, I feel no play in the shaft. Nevertheless, rattle it does.
Does anyone have a preference as to brand of replacement water pump for a 1985 300D, or is one brand pretty much the same as any other, as long as it comes with a one-year warranty?
RE: Diagnosing overheating and no get-up-and-go - Greazzer - 09-20-2012
Go with the LASO. I would give you mine for free if I could find the dam box which had all my odds and ends junk in my garage. Hating my fatigue and disorganization at times.
I don't need it anymore ... EWP for me by Davis-Craig.
RE: Diagnosing overheating and no get-up-and-go - sassparilla_kid - 09-20-2012
(09-20-2012, 04:02 PM)JustPassinThru The little breather, it turns out, does not exist after 1981.
My car is an '82 and it has one, Captain's car is also an '82, and it has one
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-20-2012
Dropped in to the Mercedes of Tacoma parts counter this evening, they want $153 plus tax for a water pump ($38 of which is the core exchange). Decided to buy one from NAPA, # 41160. Lifetime warranty, $41 including tax. I see that PartsGeek sells it for only $14.70 but I need to put it in ASAP.
You are correct about later models having the bypass; I was just quickly looking at
http://mercedessource.com/node/7722
and didn't catch the fine print underneath, "Will fit some later models". At any rate, there isn't one on my failed one, nor does NAPA's computer show one for an '85.
I am much more worried at the moment about what a local indie told me this afternoon: that soot in the coolant is a sign of the head lifting from the block, letting exhaust gasses get by the head gasket. He suggested I fill the cooling system with just water and go drive it hard for 30 miles, then drain it. If it shows soot again, then...well, I guess it's time to move over to my other 300D...
RE: Diagnosing overheating and no get-up-and-go - sassparilla_kid - 09-22-2012
Or maybe get a thicker head gasket?
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-22-2012
(09-22-2012, 12:52 AM)sassparilla_kid Or maybe get a thicker head gasket?
Maybe. But even so, if I have to pull the head I'd want to get it machined, and maybe the valves overhauled. And a new timing chain, guide, tensioner. And what the heck, might as well port the head too. Expensive. My budget is very tight at the moment. Might have to sell a few goodies.
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-24-2012
The new water pump is now in, to go with the new thermostat. I notice that the new water pump, though it doesn't freewheel, spins easily. The old one has a little resistance.
Also, I've swapped-over the radiator from my other 300D. It's an original Mercedes (has the tri-star logo) Behr and the previous owner says it was put in only a couple years (less than 10,000 miles) ago. The overflow nipple has been replaced with a brass fitting. First I flushed this radiator out (there was quite a bit of rust in it, as the other 300D had sat for a long time, perhaps a year, out in a sheep pasture) with a garden hose. I noticed, water flushes noticeably more freely through this one than it did through the old radiator, so I conclude the old radiator (no brand or logo I can find, maybe a Nissens? Modine?) was badly clogged. When I'm sure my blue 300D isn't overheating any more, I'll remove the end caps from the old one and see just how badly clogged it is.
I also pulled the other (1983) 300D's cooling fan. It's six-blade metal, the one on my blue (the one that overheated) 300D is 9-blade plastic. Testing it in my hand, resistance of the viscoelastic clutch seems the same on both, so I put the nine-blade plastic back in my blue 300D. I have an old Thorsen's 10 mm open-end wrench which removes and installs the four cooling-fan bolts just fine, it doesn't round them at all. It has a shorter head than usual and apparently is milled to very tight tolerance.
Installation of the water pump required loosening the alternator belt. Also, I notice that my power steering pump belt is loose.
I don't have the recommended tool for measuring V-belt tension, the Krikit (made by Gates). Is it possible to simply adjust the belt-tensions correctly, by the old-fashioned method of "press down with your finger on the belt halfway between the crankshaft pulley and the device's pulley, it should depress one-half inch"?
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-24-2012
I went ahead and just adjusted the V-belts to 3/8-inch of slack. Feels right.
Took it for a test drive and...shot to 110 during the 2-1/2 mile drive around the block (a very long block).
Took the old thermostat and tested it in a glass saucepan on the stove with a candy thermometer. The thermometer shows 211-212 in boiling water, so I know it's good. This thermostat opens at...
...202 Fahrenheit, equals 94.4 Celsius. Tried three times, saw 202-205 every time.
Hmm. I'll test the new thermostat as soon as the car cools down.
Well well well...the new thermostat opens at...
...195 Fahrenheit, equals 90.5 Celsius.
Looks like that bad batch of thermostats which DeliveryValve has warned of, is still being sold by MB dealers.
I think I'll try the thermostat in my other 300D, the one that's been sitting a year...
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-24-2012
The more-than-a-year-old 80-degree thermostat out of my other (silver) 300D opens at...
160 Fahrenheit = 71.1 Celsius.
Also, at maximum opening, the gap is about 6 millimeters. The other two opened only about 2-3 millimeters.
So, now to install this one in my blue 300D and go for a drive...
...back from the road test. It's fluctuating wildly now, from 80 degrees at 35 MPH to 110 degrees at 55 MPH with the gas pedal floored; at this point I pulled over to the shoulder, pulled a U-turn, and...it dropped within a few seconds to under 100. Perhaps there is air in the system.
So...as I understand it:
1. In the first instance of overheating...I had a water pump which was stiffly turning, thus I presume there was slippage, it was not pushing water as hard as it should; also, a clogged no-name-brand radiator; and, a thermostat which was opening only at 94, and then was only opening to a gap of about 2 millimeters.
2. Then, with a new thermostat but still the old water pump (which had begun to rattle) and clogged no-name-brand radiator...it was still overheating. The new thermostat was not significantly better than the failed old one. What is interesting is that it took the old thermostat more than a year to fail to the point where its performance was approximately equal to the poor performance of the new one.
3. With a new water pump and a fresh, better radiator, the new thermostat was still not opening enough, so, while the temp gauge did not shoot all the way to 120, it did hit 110 --it was still not able to cool the engine satisfactorily...
and
4. With the new water pump, fresh, better radiator and a very old thermostat tested to open at 71 and to open to a much wider gap than the newer ones (6 mm versus 2-3 mm)...temperature, at the moment, is fluctuating wildly, but never above 110.
Tomorrow I'll burp it and then try another road test. Probably should flush it again too. An indie recommended Lubro Moly Radiator Cleaner, I'll put a can of that through.
RE: Diagnosing overheating and no get-up-and-go - sassparilla_kid - 09-25-2012
Have you considered the possibility that maybe it is a faulty gauge or sending unit? I know my car always reads funky temperatures, but I am pretty confident one of these two is the culprit, and that it actually isn't running too hot
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-25-2012
With all three thermostats, it was clear from the behavior of the temp gauge when the thermostat was opening: slow rise to opening temperature, then slightly faster rise to operating temp. The gauge showed the same opening temperature for each thermostat, as I found by testing on the stove with the candy thermometer. So, I presume the sending unit and the gauge are accurate.
After the car cooled down a bit tonight, I squeezed the upper radiator hose; there's nothing in it but air. So I'm pretty sure the reason it's fluctuating now is, it needs burping.
It's very easy to burp my cooling system, because I have a Prestone flushing-tee plumbed in at the highest point in the system. All I'll have to do tomorrow morning, is slightly loosen the upper radiator hose, then, while idling the car as it approaches thermostat-opening temperature (71 C, in my case), and with both the cabin heater and the block heater on, run water in from the garden hose through the flushing-tee slowly, until there is overflow from the radiator hose.
I did drain it again this morning, while installing the fresh radiator, and saw no soot in the coolant THANK YEWW JEEZUS!
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-25-2012
Burped it this morning, just got back from the test drive. Operating temperature is now 80 C. Hard acceleration does not send it up. If I brake to a hard stop from 60 MPH, it spikes to ...82. I got stuck behind a school bus for a few minutes, it might have sneaked up to 81, and when I accelerated from the idle it just might have touched 83 before settling quickly to 80. And so, I deem the problem solved...
...I think. However, there is this nagging suspicion ...I vaguely remember reading somewhere, that there is an optimum operating temperature for the OM617a for maximum efficiency and longest life, and this little voice keeps insisting that it is higher than 80 C. Does anyone happen to know what this "optimum" operating temperature is? And, better yet, why?
Also, when I got back home, I did the rev-it-to-3000, press-the-stop-lever test. The cooling fan took about two revolutions after motor shutoff, to stop. Should I be worried?
RE: Diagnosing overheating and no get-up-and-go - JustPassinThru - 09-26-2012
No expert commentary? I guess, then, that what I've found through Google, that 80-85 C is good, must be the truth. Air temperatures here were around 55-65 during testing, so I suppose when we get a hot day it'll exceed 85.
Moral of story: if it's overheating...
1. Test the thermostat on the stove with a candy (or meat) thermometer. If it doesn't open between 71 and 80 C, or if it opens to a gap of less than 6 or 7 millimeters, reject it. Even if it's a new one from the Mercedes dealership parts counter.
2. Test the radiator. Water from a garden hose put at a medium flow rate into the upper hose connection, should flow out through the lower two connections as fast as the hose puts it in. Be careful to always have the radiator tilted so water doesn't get into the transmission fluid cooler inlet and outlet fittings.
and
3. A water pump can fail without making noise at first, and without there being any shaft play. I had to take the fan and pulley off, and turn the shaft directly by hand, before I could feel that the shaft was turning stiffly --I guess the water pump bearings were in the early stage of seizing up.
Case closed.
Hi-Ho Silver,
Awayyyy...