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+--- Thread: OM606.962 Valve Float @ raised boost? (/showthread.php?tid=8162)
OM606.962 Valve Float @ raised boost? - jav1 - 12-19-2018
I'm in the process of tuning my OM606.962 / DSL-1. I have an upgraded VNT turbo and larger intercooler. I'm running about 2bar of boost (3bar absolute) in an otherwise stock engine.
I believe I'm experiencing some exhaust valve float at around 4500 RPM. Anyone have any experience with this?
RE: OM606.962 Valve Float @ raised boost? - barrote - 12-19-2018
Usually it comes at low revs when u thr in first and second gear. Engine start to spit and unloads lifters... so u notice it right away. Lots of hammering and white smoke.
Anyhow an upgrade is always a must.
I got very strong spring available if u need pm.
Regards
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-19-2018
I'm having a problem getting past 4500 RPM... which I thought should be no problem on a stock 606? When I get close to 4500 RPM- I don't get white smoke- I get black smoke even though fuel and boost are the same as at 4400 RPM. I also get this very strange noise which doesn't show up very well in my log data. The concern is that the exhaust valves are not sealing at the end of the exhaust stroke due to high exhaust pressure? Has anyone experienced this?
I've though of installing heavier exhaust valve springs but I have 2 concerns. Camshaft wear AND, if this can be done without pulling the head? I could also just limit my RPM to around 4400 and be done with it but I'd like to understand if in fact this is normal on a stock 606 with 2 bar boost?
RE: OM606.962 Valve Float @ raised boost? - erx - 12-19-2018
I dynoed stock engine with Holset HX52 and 3.5bar boost to 6000rpm and no problem. What turbo you have and what is EGP?
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-19-2018
I have a gt2056V... not sure on EGP since my exhaust Map sensor broke. I should have a new one installed tomorrow. DO you know your EGP @ 3.5bar boost? I would presume around 4.5bar?
RE: OM606.962 Valve Float @ raised boost? - erx - 12-19-2018
(12-19-2018, 03:12 PM)jav1 I have a gt2056V... not sure on EGP since my exhaust Map sensor broke. I should have a new one installed tomorrow. DO you know your EGP @ 3.5bar boost? I would presume around 4.5bar?
Yes it was about 4.5bar egp. We couldn't get over 3.2bar boost at first time but then we found out that we had 0,7bar backpressure in downpipe. I upgraded to 4" exhaust and we got 3.5bar boost. After that I upgraded to stiffer valve springs and it went over 3.5bar.
You can't say anything before you know your egp, maybe it's over 4bar and engine starts to choke. It's quite small turbo and you have to make sure that actuator is moving very precisely and is holding boost/egp ratio right.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-19-2018
So the 3.5 bar boost was with stiffer valve springs? Yes- turbo is small but is used on 3.2 liter diesel so I'm hoping it will be OK with my 3 liter. I know vanes are wide open and I have 3" exhaust so if there is a restriction- its the turbos exhaust section.
I doubt I have 4.5 bar EGP but who knows? I installed Chinese 7 bar map that didn't last very long. I have a 5 bar GM coming tomorrow.... we'll see what it is BUT- to be sure- your 4.5 bar was with the stiffer valve springs.. correct?
RE: OM606.962 Valve Float @ raised boost? - erx - 12-19-2018
(12-19-2018, 03:40 PM)jav1 So the 3.5 bar boost was with stiffer valve springs? Yes- turbo is small but is used on 3.2 liter diesel so I'm hoping it will be OK with my 3 liter. I know vanes are wide open and I have 3" exhaust so if there is a restriction- its the turbos exhaust section.
I doubt I have 4.5 bar EGP but who knows? I installed Chinese 7 bar map that didn't last very long. I have a 5 bar GM coming tomorrow.... we'll see what it is BUT- to be sure- your 4.5 bar was with the stiffer valve springs.. correct?
it made 3.5bar boost with stock springs after I put better exhaust. From which 3.2 engine your turbo came from? I don't know how many different versions of gt2056v's there are but I belive it's even smaller than om606 stock turbo. I use gt2359v which is a little bigger than stock om606 and it spools instantly.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-19-2018
2008 e320cdi - sorry, that's a 3.0 liter not 3.2. It's NOT smaller than the stock KKK turbo but it is smaller than the gt2359v. I tried to find gt2359v but I could not find a good one when I needed it. I read many great reviews on the gt2056v- it's supposed to have better aerodynamics (newer generation) than the 2359...and I do like it... I'm just concerned the turbine housing may be a bit too restrictive for 5000RPM? I'll know soon.
So your stock valve springs supported 6000 RPM with 4.5bar EBP?
RE: OM606.962 Valve Float @ raised boost? - erx - 12-19-2018
(12-19-2018, 04:18 PM)jav1 2008 e320cdi - sorry, that's a 3.0 liter not 3.2. It's NOT smaller than the stock KKK turbo but it is smaller than the gt2359v. I tried to find gt2359v but I could not find a good one when I needed it. I read many great reviews on the gt2056v- it's supposed to have better aerodynamics (newer generation) than the 2359...and I do like it... I'm just concerned the turbine housing may be a bit too restrictive for 5000RPM? I'll know soon.
So your stock valve springs supported 6000 RPM with 4.5bar EBP?
Yes first time when we couldn't get over 3.2bar boost we tried one pull to 6500rpm and no different sound or white smoke.
Do you have black smoke and enough fuel on 4500rpm when it starts to cut? If you are 100% sure that vanes are completely opened and there is enough fuel then it should go easily over 2 bar boost.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-19-2018
it's tough to be sure on the smoke color because that test was at night on the highway. For sure there was smoke... i thought black but it may have been white? Also for sure it was right at 4500 and I was pushing just under 2 bar of boost about 27psi on my gauge and in the log. The truck just stopped accelerating, started to smoke and made a really strange sound like it was on a rev limiter. I immediately lifted off the gas pedal and the transmission shifted- which put me at a lower RPM and then everything was fine. This has happened a few times and the logs all show good boost, good fuel , vanes wide open and nothing obvious to explain why the engine behaves that way...
Baldur suggested it might be valve float and it makes sense. I've also read that the stock valve springs are only good for about 45 pounds so if the exhaust is at even at 3.5-4 bar absolute and the piston is moving down after the exhaust stroke- it makes sense that forces COULD keep the valve from sealing?
RE: OM606.962 Valve Float @ raised boost? - firen456 - 12-20-2018
Had valve float with a HE351CW 10cm housing, cast manifold from about 5000rpm @2.4bar. Stronger valve springs helped to cure this. This issue is more common than most of us think. I know minimum three OM engines from friends cars where valve float was present.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-20-2018
has anyone changed valve springs without removing the head? If this could be done without pulling the head then I may want to try that (If I find that EBP is above 4Bar absolute). Also- I'd probably only want to change the exhaust valve springs and increase the spring force about 50%... I wouldn't want to double the spring force since my goal is only to be able to rev up another 500-700 RPM to about 5000-5200 RPM because my OEM transmission controller shifts at around 4900 RPM @ WOT.
RE: OM606.962 Valve Float @ raised boost? - firen456 - 12-20-2018
yes, already upgraded some enines with the head on them. You just have to turn the piston on tdc. You can take early CDI exhaust springs with part number: 6110530220. They fit plug and play.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-20-2018
Thank you firen456,
But I think there is a problem- In this thread - post #88:
http://www.superturbodiesel.com/std/showthread.php?tid=6521&page=2
It would appear that part # 6110530220 spring is the same as the stock OM606 exhaust spring … it's just the new (superceded) number. Someone was supposed to confirm that it was in fact stiffer but they never did (on that thread anyway)? Or... has it been confirmed since then?
RE: OM606.962 Valve Float @ raised boost? - firen456 - 12-20-2018
first CDI springs were the strong ones in in and ex. Then they changed in to the weaker ones in intake and left ex strong. The 6110530220 spring is the stron exhaust spring. I compared them to the OM60x springs and it's stronger.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-20-2018
Yeah- there was quite a lot of talk about this and the way I read it (and I've now re-read it 3 times) was .... Yes with the CDI engine, the intake spring was made weaker BUT the exhaust spring was left "the same"- except they changed the part number twice.
And by "the same" I believe that means it was the same spring as the original OM606.962 exhaust spring.
One guy did compare an old OM606.962 exhaust spring against a NEW 61105300220 on a bolt and found the new one compressed less than the old one BUT... the size of the spring, wire and all, was the same. It was my understanding from that- that the "stiffness" of the new spring was just because it was NEW - not because it was really a higher rate spring?
RE: OM606.962 Valve Float @ raised boost? - erx - 12-20-2018
2 years ago before I did spring swap I tested exhaust valves and they start to bleed from 3bar pressure and at 4bar they blow all air through opened intake.
![[Image: 64vBR2D.jpg]](https://i.imgur.com/64vBR2D.jpg)
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-20-2018
Thats fantastic! Did you test again after the new spring?
RE: OM606.962 Valve Float @ raised boost? - erx - 12-22-2018
(12-20-2018, 05:49 PM)jav1 Thats fantastic! Did you test again after the new spring?
I didn't test it with new springs because I tested stock springs on spare engine. Only difference I noticed after spring swap is that engine is making a little louder noise on idle and it made a little more boost. Springs came from KMcams and they were about twice as stiff, I don't remember any numbers.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 12-23-2018
I installed my new exhaust map sensor and I am seeing just over 4 bar absolute... which I suspect is causing exhaust map float at higher rpm... seems ok in first gear but not in second or higher.
RE: OM606.962 Valve Float @ raised boost? - Ecto - 03-14-2019
I think i had a similar problem like you.
After reading your thread about your fuel delivery system i am pretty sure i know whats causing the problem.
First: the original lift pump is garbage. The pressure output oscilates and has quite high peak pressures which causes oscilating engine sound on idle.
Second: I had only bad experiences with a check valve on the suction side. It can cause steaming an bubbling inside the lines when the flow is high. And thats exactly what I am thinking is happining to you. When your lift pump pumps more and more fuel, the fuel starts to "boil" inside the suction lines which causes gas inside the lines. This gas causes retarded timing and less fuel being injected.
This problems were happining in low gears, i think due to the higher acceleration the ball inside the valve wanted to close the valve.
After i threw out the check valve and upgraded to a 044 bosch pump, my issues were gone.
Edit:
Here is a video, the sound on the end of first gear:
https://youtu.be/0ElqlNd6ios
RE: OM606.962 Valve Float @ raised boost? - jav1 - 03-14-2019
It's funny you should bring this up because over the winter, I have had problems with my fuel system. I don't "think" that is the cause of my valve float because I was having that problem before winter and it "seems" exhaust back pressure related.... but, it's an interesting idea! BTW- the sound at the end of 1st gear in your video is similar to mine except that mine is about 100 times worse and aslo has a large smoke component!
Sorry this is long but I need to explain my reasoning and I'd love your input.
On the fuel system, before winter I removed the pre-filter, replaced all the clear lines and O-rings and added the check valve. I had no bubbles in my fuel stream whatsoever.
On 2 different, REALLY REALLY cold days, my truck left me stranded and the problem was the pump was not getting fuel. The tank had plenty of diesel and the diesel wasn't gelled because I could suck some out from the tank fill and it was fine. I immediately suspected the check valve except that didn't make sense because the truck started fine in the morning after sitting outside all night during the coldest times of night, and ran fine in the morning for about 25 minutes. It was only after driving for about 20 minutes that I started to loose power and eventually, the engine died. When it died, you could NOT suck fuel through the line with either a primer bulb- or full vacuum from a pump... the fuel line appeared completely blocked! I actually put a heat gun on the check valve, which is under the truck in the fuel line right below the drivers seat. Even with heat gun on the valve the valve too hot to touch, the fuel would NOT flow.
I put the truck in a warm garage for the night, and the next morning, fuel flowed fine as if nothing was ever wrong EXCEPT- now I had bubbles in my fuel line going to the suction pump. The bubbles were being pumped into the filter but the line coming out of the filter to the IP had no bubbles.
I reasoned that the most likely cause of my problem was water in my fuel tank that froze and got sucked into the pick-up tube causing a blockage since my pickup is just rubber tube with no strainer screen. Once it melted, the blockage was gone. This stalling problem only ever occurred during temperatures well below freezing- but the truck drives fine all other times. Only - now my lines have bubbles in them. I reasoned that perhaps my heating the check valve and trying to suck fuel with full vacuum, I may have introduce a leak somewhere in the line... which I planned to address this weekend. I plan to:
1) Pulling the tank and redoing the fuel pick-up and return line. On the pick-up, I'm making it 8mm ID (steel line) with a mesh mushroom style screen on the end so if there's any ice in the tank, it can't be sucked tight into the tube and create an obstruction.
2) I'm extending the return line down to the bottom of the tank - below the fuel level so no air can get into the return line.
3) I'm running 8m ID solid lines from the tank to engine bay.
4) I'm getting rid of the check valve.
I hope this solves, my freezing temperature fuel starvation problem, air bubbles in my fuel supply and with no check valve, less restriction but no fuel drain back over night.
I'll see if this fixes my valve float issue but I suspect it wont.
I think my valve float issue is exhaust pack pressure related from the turbo. I recently purchased a bigger VNT turbo but it will be a while before I can install it. My thought is that while the existing gt2056 is great and spools instantly, the exhaust side is too restrictive with full fueling and high revs on the 606. I now have a GT2359 to test and I'll be able to see what the exhaust back pressure difference is and if that cures the valve float.
RE: OM606.962 Valve Float @ raised boost? - barrote - 03-15-2019
(03-14-2019, 10:35 AM)Ecto I think i had a similar problem like you.That hammering id due to air trapped in pump elements...in high output pumps . Most do that .
After reading your thread about your fuel delivery system i am pretty sure i know whats causing the problem.
First: the original lift pump is garbage. The pressure output oscilates and has quite high peak pressures which causes oscilating engine sound on idle.
Second: I had only bad experiences with a check valve on the suction side. It can cause steaming an bubbling inside the lines when the flow is high. And thats exactly what I am thinking is happining to you. When your lift pump pumps more and more fuel, the fuel starts to "boil" inside the suction lines which causes gas inside the lines. This gas causes retarded timing and less fuel being injected.
This problems were happining in low gears, i think due to the higher acceleration the ball inside the valve wanted to close the valve.
After i threw out the check valve and upgraded to a 044 bosch pump, my issues were gone.
Edit:
Here is a video, the sound on the end of first gear:
https://youtu.be/0ElqlNd6ios
Th
But it can be noticed that your engine actually acelerated well, wich in most it isn't possible.
RE: OM606.962 Valve Float @ raised boost? - barrote - 03-15-2019
I think my valve float issue is exhaust pack pressure related from the turbo. I recently purchased a bigger VNT turbo but it will be a while before I can install it. My thought is that while the existing gt2056 is great and spools instantly, the exhaust side is too restrictive with full fueling and high revs on the 606. I now have a GT2359 to test and I'll be able to see what the exhaust back pressure difference is and if that cures the valve float.
The fuel problem cam be and must be repaired by using a series pump 250lts min at least.
All engines with superpumps need one.
The valve floating is another matter wich can only be solved with stronguer springs. Or running lower EBP.
There are ways to deal with it . Vnt generates a lot of EBP.
And gt 20 is just to smal for 606.
RE: OM606.962 Valve Float @ raised boost? - jav1 - 03-15-2019
(03-15-2019, 02:51 AM)barrote I think my valve float issue is exhaust pack pressure related from the turbo. I recently purchased a bigger VNT turbo but it will be a while before I can install it. My thought is that while the existing gt2056 is great and spools instantly, the exhaust side is too restrictive with full fueling and high revs on the 606. I now have a GT2359 to test and I'll be able to see what the exhaust back pressure difference is and if that cures the valve float.
The fuel problem cam be and must be repaired by using a series pump 250lts min at least.
All engines with superpumps need one.
The valve floating is another matter wich can only be solved with stronguer springs. Or running lower EBP.
There are ways to deal with it . Vnt generates a lot of EBP.
And gt 20 is just to smal for 606.
I don't have the superpump- just the stock 606 pump with Baldurs controller. You know the GT20 actually works pretty well on the 606. I get 2 bar of boost with 3 bar of ebp… the problem is at 4500 RPM, EPB continues to rise and the valves start to float.
RE: OM606.962 Valve Float @ raised boost? - barrote - 03-15-2019
Then u have to do something about it... waste gas out or harder springs...
RE: OM606.962 Valve Float @ raised boost? - jav1 - 03-15-2019
I'm going to try the GT23 before I do springs
RE: OM606.962 Valve Float @ raised boost? - X Double Dot - 01-13-2022
curious what all came out of this. Did you try the stiffer springs or the large exhaust housing turbo? Considering adding a egp gauge to my setup to confirm i'm not running into a similar issue