Chris Wilson Posted May 27, 2007 Author Share Posted May 27, 2007 Those who have suffered oil pump seal failure: Have you had a crank damper failure on that engine? Thanks. Quote Link to comment Share on other sites More sharing options...
Mike_Mac Posted May 28, 2007 Share Posted May 28, 2007 Those who have suffered oil pump seal failure: Have you had a crank damper failure on that engine? Thanks. Yes - Outer ring had fallen off completely and was found in the undertray. The belt was still running on what was left and there was no noticeable difference in the way it drove. Quote Link to comment Share on other sites More sharing options...
dandan Posted May 28, 2007 Share Posted May 28, 2007 Thanks for posting up the pics fellas, very useful. Anyone got any pics of: Drain hole region Cracked/leaky new pumps PHR/Envy modified pumps I didn't get round to checking the dipstick retention as I couldn't find my spring balance. I'll try to do it at work tomorrow if I can find one there. Quote Link to comment Share on other sites More sharing options...
Nic Posted May 28, 2007 Share Posted May 28, 2007 I had 3 front oil seal failures in as many months on my first engine. Verdict was worn engine pressuring crank case, no evidence to prove this apart from worn bores/rings. No crank damper failure. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 Never had a problem with crank damper, i see where your going Chris, but then the crank bearings would show up before it developed an oil pump problem, Here are some pics: http://www.imagestation.com/picture/sraid225/p6e66d322c63833ad9ffcd103f8ca3b5e/e950e009.jpg The drain hole, (not sure if this one has been opened out?) http://www.imagestation.com/picture/sraid225/p26e9825b303dfaf8354fa13ac0ad3511/e950e006.jpg A pump that someone has ported, and the relevant sizes. http://www.imagestation.com/picture/sraid225/pa4dec47616b1e6e3e5921b2acc850246/e950e002.jpg A PHR modded pump. Quote Link to comment Share on other sites More sharing options...
JohnA Posted May 28, 2007 Share Posted May 28, 2007 I...All cars had no crank seal failure....only pushed out dipsticks..... Very interesting, that's a 9" nail in the 'crankcase pressure' theory coffin. Quote Link to comment Share on other sites More sharing options...
Guest 87gtNOS Posted May 28, 2007 Share Posted May 28, 2007 Wow guys, I am seeing how this works now. I wonder, could the seal be installed too far into the housing, thus allowing the center oil pump rotor to rub on the inner lip of the seal? That would cause instant failure! Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 Wow guys, I am seeing how this works now. I wonder, could the seal be installed too far into the housing, thus allowing the center oil pump rotor to rub on the inner lip of the seal? That would cause instant failure! No! as there is a shoulder that prevents this, also should you drive the seal in to far, it will then block the drain hole and cause failure that way. Quote Link to comment Share on other sites More sharing options...
Guest 87gtNOS Posted May 28, 2007 Share Posted May 28, 2007 No! as there is a shoulder that prevents this, also should you drive the seal in to far, it will then block the drain hole and cause failure that way. Yes, a shoulder to stop the outside diameter of the seal from going in too far, however, that may be too far for the center of the seal? Just an idea..... Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 Yes, a shoulder to stop the outside diameter of the seal from going in too far, however, that may be too far for the center of the seal? Just an idea..... Sorry but Toyota are not that silly,the spline drives for the oil pump don't project as far as the shoulder, and like i said you would get failure anyway due to even small amounts of oil building up and pressurising due to not being able to escape. Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 28, 2007 Share Posted May 28, 2007 Or even a spring balance would do the job. I don't have my car with me now but could do it tomorrow on 2 different cars. Please do Any chance you have an oil pump laying around so you could measure the pull out load for the seal? Quote Link to comment Share on other sites More sharing options...
dandan Posted May 28, 2007 Share Posted May 28, 2007 I will try my best tomorrow but have a jam packed day at work. I'll probably borrow the spring balance and go from there.... I do have a spare pump and seal but it's on an assembled engine and I don't really want to pull it out just for that to be honest. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted May 28, 2007 Share Posted May 28, 2007 Any chance the oil pump drive gear machined on the crank nose could make contact inner sealing edge if thrust bearings were worn enough to cause enough end-float or "crank-walk"? Perhaps aided with a depression in c/case pressure which might momentarily pull seal edge/lip in to touch machined pump drive gear? Probably been covered already, but just as a thought, also by sound of Jamies "mayonaise" may be looking at too many symptoms of faults resulting in crank seal failures. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 Thats pretty much the US crank walk theory,except that they think the crank movement causes the oil pump to wear, result, oil pressurising the seal, seal fails. The reason IMO why it won't hold up, is that the oil pump will probably fail or cause lack of oil pressure before it could actually contact the oil seal, and it would have to have at least 3mm movement probably more! before it could do this. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 Please do Any chance you have an oil pump laying around so you could measure the pull out load for the seal? Don't actually think this would provide a realistic guide, as there are to many variables, first not many seals actually push out, just the seal lips fail, and to measure this you would need the crank in place. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted May 28, 2007 Share Posted May 28, 2007 Thats pretty much the US crank walk theory,except that they think the crank movement causes the oil pump to wear, result, oil pressurising the seal, seal fails. The reason IMO why it won't hold up, is that the oil pump will probably fail or cause lack of oil pressure before it could actually contact the oil seal, and it would have to have at least 3mm movement probably more! before it could do this. As much as 3mm, I see, oh well. Haven't seen any pics of the pump drive on the crank, thought perhaps teeth might be protuding slightly further than oil pump housing therefore requiring less end-float travel to make contact with seal edge. Quote Link to comment Share on other sites More sharing options...
dandan Posted May 28, 2007 Share Posted May 28, 2007 Don't actually think this would provide a realistic guide, as there are to many variables, first not many seals actually push out, just the seal lips fail, and to measure this you would need the crank in place. A measurement with no crank in place would give "A" figure to work with compared to the dipstick ejection figure. In reality if the engine is running the friction contribution from the crank (in terms of seal retention) would be very small compared to that of the fit on the seal OD. I agree this quick test won't be exactly correct but a static pull test with no crank in place will give some sort of ballpark figure - better than nothing at least. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 True i guess, anyway although i don't think they are that accurate, i have manged to dig out an old set of fishing spring balance and on repeated tests the pressure required to pull out the dip stick is 4.5 lbs approx. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted May 28, 2007 Share Posted May 28, 2007 Another thought i've had is that Is there a possiblity the machined hole the seal sits in, in the pump housing, is "out-of-true" to where the crank sits and therefore having tighter contact on on an area and loose contact to opposite allowing oil to escape? Or does the oil pump ensure the crank is true/centric to seal? Are the new seal designs identical i take it? Not exactly same situation but as part of Porsche's neverending battle to remedy the Rear Main Oil seal leaks on the M96 onwards engines they supplied us with a tool we use check crank is central in crank case (bit quicker than using verniers), occasionally due to machining errors, cranks were not acceptably central to crankcase aparently causing the seal in the crankcase to leak and this would require full engine strip and replace the crankcase casings to remedy. There's also various modified guises of the seal, latest no longer using a tension spring seems to do the job ok, still seen a few leak tho, but a lot less of an issue. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted May 28, 2007 Share Posted May 28, 2007 Good point, as the pump case is bolted to the front of the block, so in theory there is the possibility for misalignment, but the amount of oil suddenly expelled suggests that there is a pressure build up, but it may well explain the reason why some people have a slightly leaky seal, that never develops further. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 28, 2007 Author Share Posted May 28, 2007 Never had a problem with crank damper, i see where your going Chris, but then the crank bearings would show up before it developed an oil pump problem, I was wondering if the rather frail nose on the crank was getting bent when a damper ring came off, but I am clutching at straws now. I need a pump that regularly shows failed seals to do more. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted May 28, 2007 Share Posted May 28, 2007 I was wondering if the rather frail nose on the crank was getting bent when a damper ring came off, but I am clutching at straws now. I need a pump that regularly shows failed seals to do more. So if it were possible for the crank nose to marginally bend from damper separation, could this cause it to run eccentrically around seal contact face, guess this could be checked with a dial guage i situ with sump and pump removed, or a set of Vee blocks with crank removed. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted May 28, 2007 Share Posted May 28, 2007 Guess with the engine running the new pulley would be wobbling all over the shop so maybe not. Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 28, 2007 Share Posted May 28, 2007 True i guess, anyway although i don't think they are that accurate, i have manged to dig out an old set of fishing spring balance and on repeated tests the pressure required to pull out the dip stick is 4.5 lbs approx. Cheers for that Assuming the dipstick tube inside diameter is 7mm (guess - its raining too hard to go and measure) then the pressure require to produce 4.5lbs (20N) at the dipstick would be just over 5bar. That a LOT of blowby Its also going to be a lot of force in the back of a seal with a much larger surface area. If the front seal is 60mm OD and 50mm ID (again guesses) then the seal will be seeing a push-out load of 450N (over 100lbs) at the same pressure. I think its worth measuring the push-out load on the front seal if only to prove / disprove the "dip stick will pop out first if its down to crankcase pressurisation" theory. Quote Link to comment Share on other sites More sharing options...
b_have Posted May 28, 2007 Share Posted May 28, 2007 I was wondering if the rather frail nose on the crank was getting bent when a damper ring came off, but I am clutching at straws now. I need a pump that regularly shows failed seals to do more. What about the stress of a 5 Ft scaffold pole used to release the crank bolt that we keep hearing about? Quote Link to comment Share on other sites More sharing options...
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