OM60x timing chain check=2.5* advanced?
OM60x timing chain check=2.5* advanced?
89 190d timing chain check=2.5* advanced?
Checked the timing chain stretch while doing 5 new rubber intake boots, 4 new air cleaner box side bushings, some new PVC bits, and 5 new glow plugs. Used the opportunity to remove the valve cover, and check the timing chain stretch & injection timing. Weird measurement result.
The factory timing marks molded into the rubber on the balance were deteriorated on the ATDC side, but easyto read on the BTDC side. An extremely precise set of new markings were made using Microsoft Publisher, and some paper/tape. You can see from the picture how precise the new markings are. They may look slightly off from an angle, but looking strait down after rotating through each significant mark of 40BTDC, 30BTDC, 20BTDC, 10BTDC, 0BTDC, ect; revealed perfect alignment.
The weird result was that with the camshaft timing marks perfectly aligned; the crankshaft markings indicate the timing is 2.5 degrees BTDC. Even if you discredit the homemade timing marks on the paper/tape, you can still clearly see that it is coming up ahead of the " O'T " mark for the Zero degrees separation mark:
(<- ATDC <- O'T -> BTDC ->.
I cranked it up for a few seconds to re-pressurize the timing chain tensioner with oil. This resulted in the exact same measurement afterwards.
The odometer quit working years ago, but keeping up with each tank of fuel added the car should have somewhere around 400k miles on it. Based on my understanding having the chain off by 1 tooth would result in 18 degrees difference, and valves would have been impacting pistons long ago. Car runs fine, camshaft sprocket teeth look perfect, and the engine is remarkably clean and completely sludge free. Regular oil & filter changes.
To my knowledge, and the examination of 20 years of service records that came with the car, the engine has never been worked on except for a set of glow plugs in the past.
On the basis of an estimation of 1* of chain stretch per 100,000 miles I shoud be at 4 or 5 degrees at this mileage. I know that the TDC arrow indicator has some adjustment to it, but it appears to have never been moved from the dirt marks on it, and I also do not think it would have more than 2* movement in it either way. The balancer pulley cannot be off because of the factory centering pin.
The paper/tape markings are exactly spot on when viewed from above. They are elevated on the metal of the dampener and mounted on a larger diameter wheel, when you look at 20 & 30 degrees in the photo you are not looking strait down in a line of sight. If it were rotated with the 20 mark or the 30 mark strait up, and a new picture uploaded you would see what I mean. The tape/paper is elevated on a larger circumference of the pulley housing about half an inch above the timing markings on the dampener. This makes it look funny when viewed from an angle, but when looking strait down/line of sight from above each mark at each position is spot on.
Original question is why is there any measurement before TDC and not after. Even the MB manual states that a new chain should show 2* or so after 20,000 miles on a new chain after the initial break in period. This means that even with a chain that exhibited no wear it is still 4.5* off at the bare minimum, and I don't think that the timing pointer can even move more that about plus or minus 2*. This also doesn't take into account 400,000 miles.
thoughts?
ideas?
theories?
timing chain shrinkage?
bhowell_10
03-14-2014, 06:14 PM #1OM60x timing chain check=2.5* advanced?
89 190d timing chain check=2.5* advanced?
Checked the timing chain stretch while doing 5 new rubber intake boots, 4 new air cleaner box side bushings, some new PVC bits, and 5 new glow plugs. Used the opportunity to remove the valve cover, and check the timing chain stretch & injection timing. Weird measurement result.
The factory timing marks molded into the rubber on the balance were deteriorated on the ATDC side, but easyto read on the BTDC side. An extremely precise set of new markings were made using Microsoft Publisher, and some paper/tape. You can see from the picture how precise the new markings are. They may look slightly off from an angle, but looking strait down after rotating through each significant mark of 40BTDC, 30BTDC, 20BTDC, 10BTDC, 0BTDC, ect; revealed perfect alignment.
The weird result was that with the camshaft timing marks perfectly aligned; the crankshaft markings indicate the timing is 2.5 degrees BTDC. Even if you discredit the homemade timing marks on the paper/tape, you can still clearly see that it is coming up ahead of the " O'T " mark for the Zero degrees separation mark:
(<- ATDC <- O'T -> BTDC ->.
I cranked it up for a few seconds to re-pressurize the timing chain tensioner with oil. This resulted in the exact same measurement afterwards.
The odometer quit working years ago, but keeping up with each tank of fuel added the car should have somewhere around 400k miles on it. Based on my understanding having the chain off by 1 tooth would result in 18 degrees difference, and valves would have been impacting pistons long ago. Car runs fine, camshaft sprocket teeth look perfect, and the engine is remarkably clean and completely sludge free. Regular oil & filter changes.
To my knowledge, and the examination of 20 years of service records that came with the car, the engine has never been worked on except for a set of glow plugs in the past.
On the basis of an estimation of 1* of chain stretch per 100,000 miles I shoud be at 4 or 5 degrees at this mileage. I know that the TDC arrow indicator has some adjustment to it, but it appears to have never been moved from the dirt marks on it, and I also do not think it would have more than 2* movement in it either way. The balancer pulley cannot be off because of the factory centering pin.
The paper/tape markings are exactly spot on when viewed from above. They are elevated on the metal of the dampener and mounted on a larger diameter wheel, when you look at 20 & 30 degrees in the photo you are not looking strait down in a line of sight. If it were rotated with the 20 mark or the 30 mark strait up, and a new picture uploaded you would see what I mean. The tape/paper is elevated on a larger circumference of the pulley housing about half an inch above the timing markings on the dampener. This makes it look funny when viewed from an angle, but when looking strait down/line of sight from above each mark at each position is spot on.
Original question is why is there any measurement before TDC and not after. Even the MB manual states that a new chain should show 2* or so after 20,000 miles on a new chain after the initial break in period. This means that even with a chain that exhibited no wear it is still 4.5* off at the bare minimum, and I don't think that the timing pointer can even move more that about plus or minus 2*. This also doesn't take into account 400,000 miles.
thoughts?
ideas?
theories?
timing chain shrinkage?
it should be around 5* ATDC now. right??
Holset power!
(03-14-2014, 06:14 PM)bhowell_10 OM60x timing chain check=2.5* advanced?
89 190d timing chain check=2.5* advanced?
Checked the timing chain stretch while doing 5 new rubber intake boots, 4 new air cleaner box side bushings, some new PVC bits, and 5 new glow plugs. Used the opportunity to remove the valve cover, and check the timing chain stretch & injection timing. Weird measurement result.
The factory timing marks molded into the rubber on the balance were deteriorated on the ATDC side, but easyto read on the BTDC side. An extremely precise set of new markings were made using Microsoft Publisher, and some paper/tape. You can see from the picture how precise the new markings are. They may look slightly off from an angle, but looking strait down after rotating through each significant mark of 40BTDC, 30BTDC, 20BTDC, 10BTDC, 0BTDC, ect; revealed perfect alignment.
The weird result was that with the camshaft timing marks perfectly aligned; the crankshaft markings indicate the timing is 2.5 degrees BTDC. Even if you discredit the homemade timing marks on the paper/tape, you can still clearly see that it is coming up ahead of the " O'T " mark for the Zero degrees separation mark:
(<- ATDC <- O'T -> BTDC ->.
I cranked it up for a few seconds to re-pressurize the timing chain tensioner with oil. This resulted in the exact same measurement afterwards.
The odometer quit working years ago, but keeping up with each tank of fuel added the car should have somewhere around 400k miles on it. Based on my understanding having the chain off by 1 tooth would result in 18 degrees difference, and valves would have been impacting pistons long ago. Car runs fine, camshaft sprocket teeth look perfect, and the engine is remarkably clean and completely sludge free. Regular oil & filter changes.
To my knowledge, and the examination of 20 years of service records that came with the car, the engine has never been worked on except for a set of glow plugs in the past.
On the basis of an estimation of 1* of chain stretch per 100,000 miles I shoud be at 4 or 5 degrees at this mileage. I know that the TDC arrow indicator has some adjustment to it, but it appears to have never been moved from the dirt marks on it, and I also do not think it would have more than 2* movement in it either way. The balancer pulley cannot be off because of the factory centering pin.
The paper/tape markings are exactly spot on when viewed from above. They are elevated on the metal of the dampener and mounted on a larger diameter wheel, when you look at 20 & 30 degrees in the photo you are not looking strait down in a line of sight. If it were rotated with the 20 mark or the 30 mark strait up, and a new picture uploaded you would see what I mean. The tape/paper is elevated on a larger circumference of the pulley housing about half an inch above the timing markings on the dampener. This makes it look funny when viewed from an angle, but when looking strait down/line of sight from above each mark at each position is spot on.
Original question is why is there any measurement before TDC and not after. Even the MB manual states that a new chain should show 2* or so after 20,000 miles on a new chain after the initial break in period. This means that even with a chain that exhibited no wear it is still 4.5* off at the bare minimum, and I don't think that the timing pointer can even move more that about plus or minus 2*. This also doesn't take into account 400,000 miles.
thoughts?
ideas?
theories?
timing chain shrinkage?
Probably a slipped marker or harmonic balancer. I wouldnt relay on bolt marks to tell if the marker pointer has been touched. Does the pump line up where it should? Is it also off a few degrees?
Duncansport
03-19-2014, 10:01 AM #3(03-14-2014, 06:14 PM)bhowell_10 OM60x timing chain check=2.5* advanced?
89 190d timing chain check=2.5* advanced?
Checked the timing chain stretch while doing 5 new rubber intake boots, 4 new air cleaner box side bushings, some new PVC bits, and 5 new glow plugs. Used the opportunity to remove the valve cover, and check the timing chain stretch & injection timing. Weird measurement result.
The factory timing marks molded into the rubber on the balance were deteriorated on the ATDC side, but easyto read on the BTDC side. An extremely precise set of new markings were made using Microsoft Publisher, and some paper/tape. You can see from the picture how precise the new markings are. They may look slightly off from an angle, but looking strait down after rotating through each significant mark of 40BTDC, 30BTDC, 20BTDC, 10BTDC, 0BTDC, ect; revealed perfect alignment.
The weird result was that with the camshaft timing marks perfectly aligned; the crankshaft markings indicate the timing is 2.5 degrees BTDC. Even if you discredit the homemade timing marks on the paper/tape, you can still clearly see that it is coming up ahead of the " O'T " mark for the Zero degrees separation mark:
(<- ATDC <- O'T -> BTDC ->.
I cranked it up for a few seconds to re-pressurize the timing chain tensioner with oil. This resulted in the exact same measurement afterwards.
The odometer quit working years ago, but keeping up with each tank of fuel added the car should have somewhere around 400k miles on it. Based on my understanding having the chain off by 1 tooth would result in 18 degrees difference, and valves would have been impacting pistons long ago. Car runs fine, camshaft sprocket teeth look perfect, and the engine is remarkably clean and completely sludge free. Regular oil & filter changes.
To my knowledge, and the examination of 20 years of service records that came with the car, the engine has never been worked on except for a set of glow plugs in the past.
On the basis of an estimation of 1* of chain stretch per 100,000 miles I shoud be at 4 or 5 degrees at this mileage. I know that the TDC arrow indicator has some adjustment to it, but it appears to have never been moved from the dirt marks on it, and I also do not think it would have more than 2* movement in it either way. The balancer pulley cannot be off because of the factory centering pin.
The paper/tape markings are exactly spot on when viewed from above. They are elevated on the metal of the dampener and mounted on a larger diameter wheel, when you look at 20 & 30 degrees in the photo you are not looking strait down in a line of sight. If it were rotated with the 20 mark or the 30 mark strait up, and a new picture uploaded you would see what I mean. The tape/paper is elevated on a larger circumference of the pulley housing about half an inch above the timing markings on the dampener. This makes it look funny when viewed from an angle, but when looking strait down/line of sight from above each mark at each position is spot on.
Original question is why is there any measurement before TDC and not after. Even the MB manual states that a new chain should show 2* or so after 20,000 miles on a new chain after the initial break in period. This means that even with a chain that exhibited no wear it is still 4.5* off at the bare minimum, and I don't think that the timing pointer can even move more that about plus or minus 2*. This also doesn't take into account 400,000 miles.
thoughts?
ideas?
theories?
timing chain shrinkage?
Probably a slipped marker or harmonic balancer. I wouldnt relay on bolt marks to tell if the marker pointer has been touched. Does the pump line up where it should? Is it also off a few degrees?
(03-19-2014, 10:24 AM)john if you just changed the glowplugs it should be easy to remove the GP, Injector and prechamber and do a TRUE tdc test and new timing marks on the balancer.No need to disturb the injector or prechamber, or for that matter even the intake manifold.
Just drill out a glow plug housing and hook some spaghetti hose up to it. Drop the hose into water and very slowly rotate the engine until the bubbles just stop. That is TDC. You should be able to nail it to the accuracy of that pointer.
(03-19-2014, 10:24 AM)john if you just changed the glowplugs it should be easy to remove the GP, Injector and prechamber and do a TRUE tdc test and new timing marks on the balancer.No need to disturb the injector or prechamber, or for that matter even the intake manifold.
Just drill out a glow plug housing and hook some spaghetti hose up to it. Drop the hose into water and very slowly rotate the engine until the bubbles just stop. That is TDC. You should be able to nail it to the accuracy of that pointer.
(03-21-2014, 01:03 PM)AlanMcR(03-19-2014, 10:24 AM)john if you just changed the glowplugs it should be easy to remove the GP, Injector and prechamber and do a TRUE tdc test and new timing marks on the balancer.No need to disturb the injector or prechamber, or for that matter even the intake manifold.
Just drill out a glow plug housing and hook some spaghetti hose up to it. Drop the hose into water and very slowly rotate the engine until the bubbles just stop. That is TDC. You should be able to nail it to the accuracy of that pointer.
Smart trick but not so acurate?
Holset power!
(03-21-2014, 01:03 PM)AlanMcR(03-19-2014, 10:24 AM)john if you just changed the glowplugs it should be easy to remove the GP, Injector and prechamber and do a TRUE tdc test and new timing marks on the balancer.No need to disturb the injector or prechamber, or for that matter even the intake manifold.
Just drill out a glow plug housing and hook some spaghetti hose up to it. Drop the hose into water and very slowly rotate the engine until the bubbles just stop. That is TDC. You should be able to nail it to the accuracy of that pointer.
Smart trick but not so acurate?
Holset power!
A silly question, if the timing hapens to be wrong wich it seems not to be the case, how could one fix it, i mean using same sprockets and chain, can one change the basic timing at the camshaft?, or the solution is new chain and sprockets? another silly question, changing the head gasket, imagine that one have to machine the flatness of the head assy, depending how much cutting and repair head gasket, that will change overall distance from center of crankshaft to camshaft center, is there any way for fixing basic timing?
thanks in advance.
regards all
FD
FD,
Powered by tractor fuel
hello fine people,
A silly question, if the timing hapens to be wrong wich it seems not to be the case, how could one fix it, i mean using same sprockets and chain, can one change the basic timing at the camshaft?, or the solution is new chain and sprockets? another silly question, changing the head gasket, imagine that one have to machine the flatness of the head assy, depending how much cutting and repair head gasket, that will change overall distance from center of crankshaft to camshaft center, is there any way for fixing basic timing?
thanks in advance.
regards all
FD
FD,
Powered by tractor fuel
(03-23-2014, 03:10 PM)barrote hello fine people,The timing should only change if the parts wear. Thus replacing the parts should put the timing back where it should be. As for milling the head/block. Any height removed needs to be made up for in a thicker head gasket. Again the correct parts will put the timing in the right place.
A silly question, if the timing hapens to be wrong wich it seems not to be the case, how could one fix it, i mean using same sprockets and chain, can one change the basic timing at the camshaft?, or the solution is new chain and sprockets? another silly question, changing the head gasket, imagine that one have to machine the flatness of the head assy, depending how much cutting and repair head gasket, that will change overall distance from center of crankshaft to camshaft center, is there any way for fixing basic timing?
thanks in advance.
regards all
FD
(03-23-2014, 03:10 PM)barrote hello fine people,The timing should only change if the parts wear. Thus replacing the parts should put the timing back where it should be. As for milling the head/block. Any height removed needs to be made up for in a thicker head gasket. Again the correct parts will put the timing in the right place.
A silly question, if the timing hapens to be wrong wich it seems not to be the case, how could one fix it, i mean using same sprockets and chain, can one change the basic timing at the camshaft?, or the solution is new chain and sprockets? another silly question, changing the head gasket, imagine that one have to machine the flatness of the head assy, depending how much cutting and repair head gasket, that will change overall distance from center of crankshaft to camshaft center, is there any way for fixing basic timing?
thanks in advance.
regards all
FD
yep i understand that concept, and by the way one mm in head assy height wont afect that much, unless one have a racing engine where valve opening and closure is of that 2% more power needed to make the diff , and in this case one could adjust head height, or custom camshafts to get that result.
was curious about the MB repair manual wich states how to mesure valve opening , but it does not refer what to do in case the 2mm opening is of the 14º.
read somewhere that M104 has stiffer valve springs, and they are just plug and play to the 605/6, does anyone know anything about that?
regards
FD,
FD,
Powered by tractor fuel
hy there alan,
yep i understand that concept, and by the way one mm in head assy height wont afect that much, unless one have a racing engine where valve opening and closure is of that 2% more power needed to make the diff , and in this case one could adjust head height, or custom camshafts to get that result.
was curious about the MB repair manual wich states how to mesure valve opening , but it does not refer what to do in case the 2mm opening is of the 14º.
read somewhere that M104 has stiffer valve springs, and they are just plug and play to the 605/6, does anyone know anything about that?
regards
FD,
FD,
Powered by tractor fuel
(03-25-2014, 07:15 AM)barrote hy there alan,The "thicker" MB head gasket is only 0.2mm thicker. Installing that on an uncut head would result in a reduction from 1:22.0 to 1:20.8.
yep i understand that concept, and by the way one mm in head assy height wont afect that much, unless one have a racing engine where valve opening and closure is of that 2% more power needed to make the diff , and in this case one could adjust head height, or custom camshafts to get that result.
was curious about the MB repair manual wich states how to mesure valve opening , but it does not refer what to do in case the 2mm opening is of the 14º.
read somewhere that M104 has stiffer valve springs, and they are just plug and play to the 605/6, does anyone know anything about that?
regards
FD,
(03-25-2014, 07:15 AM)barrote hy there alan,The "thicker" MB head gasket is only 0.2mm thicker. Installing that on an uncut head would result in a reduction from 1:22.0 to 1:20.8.
yep i understand that concept, and by the way one mm in head assy height wont afect that much, unless one have a racing engine where valve opening and closure is of that 2% more power needed to make the diff , and in this case one could adjust head height, or custom camshafts to get that result.
was curious about the MB repair manual wich states how to mesure valve opening , but it does not refer what to do in case the 2mm opening is of the 14º.
read somewhere that M104 has stiffer valve springs, and they are just plug and play to the 605/6, does anyone know anything about that?
regards
FD,
1 Guest(s)
1 Guest(s)