What I will find when I pull the pan?

[squirrl22]

Blew the oil filter on the highway- now I'm getting only 25psi pressure at idle, although 75 psi above idle.  -Not as good as the 90PSI I was geting before, I assume some bearing damage, but where?
I've pulled the valve cover and checked the cam journals- they are perfect.
Any body have a clue what I will find when I pull the oil pan?  Is it possible I could just get away with replacing the main bearings?
I would love it if I only had to go in thru the bottom.
Any advice would be appreciated!

[jimfoo]

Well, technically I think that is still within spec. I am guessing you will have to use plastigauge to find the wear.

[squirrl22]

Thanks, Jim.  good point- may not be any visable damage.  I'm hoping I don't have to check the piston  wrist pin bushings.  Do you have any experience with this?
 
I've pulled the engine, I have it on the engine stand, And I'm pulling the oil pan tonight.  I would love it if I only had to replace rod and/or main bearings,  and didn't have to mess with pulling the cyl head and pistons. -
Just got done having a re-built cyl head put on.

[burnt_servo]

i'm starting to see a pattern with all the engines i've been pulling apart .

the upper bearing shells on the con rods tend to be worn much more if the #4 main bearing isn't a full groove bearing  .

i've also seen a lot of worn upper main bearing shell on #1 . the wear gets worse if the engine has ac on it .


if you buy your main bearing set from vw ,  you will get a full groove #4 main .  i haven't seen a aftermarket bearing set that will give you a full groove #4 ( this applies to the 1.6 turbo ....)

[jtanguay]

i'm starting to see a pattern with all the engines i've been pulling apart .

the upper bearing shells on the con rods tend to be worn much more if the #4 main bearing isn't a full groove bearing  .

i've also seen a lot of worn upper main bearing shell on #1 . the wear gets worse if the engine has ac on it .


if you buy your main bearing set from vw ,  you will get a full groove #4 main .  i haven't seen a aftermarket bearing set that will give you a full groove #4 ( this applies to the 1.6 turbo ....)

myke_w on here sells bearings.  i got mine from him

[squirrl22]

So, I should plastigauge the upper bearing shell/crankshaft, not the lower bearing. - Yes, I do have ac

No need for  full groove bearing for all the mains-just #4?  


Posted: Mon Apr 07, 2008 3:26 pm    Post subject:    

--------------------------------------------------------------------------------
 
i'm starting to see a pattern with all the engines i've been pulling apart .

the upper bearing shells on the con rods tend to be worn much more if the #4 main bearing isn't a full groove bearing .

i've also seen a lot of worn upper main bearing shell on #1 . the wear gets worse if the engine has ac on it .

[burnt_servo]

if i remember corectly , oil gets pumps to #4 main , and from there it gets pumped to the rod bearings . with a full groove bearing on #4 , you get 360 degree's rotation of full oil presure to the rod bearings .

with only a grooved upper bearing in #4 ( like the other main bearings ) , you only get full presure to the rod bearings during 180 degree's of the cranks roation , as the hole that feeds the oil to the rods  gets covered by the extra material in the non grooved lower bearing .

in a "vw"  bearing kit , you will get a thrust bearing upper and lower , and 3 plain lower main bearings and 5 grooved bearings , 4 are upper bearings , and one is the lower bearing to #4 .


every jobber bearing kit i've seen so far , has only 4 grooved bearingshells  and 4 plain bearing shells  ( plus the upper and lower thrust bearing )  .

So, I should plastigauge the upper bearing shell/crankshaft, not the lower bearing. - Yes, I do have ac

No need for  full groove bearing for all the mains-just #4?  


Posted: Mon Apr 07, 2008 3:26 pm    Post subject:    

--------------------------------------------------------------------------------
 
i'm starting to see a pattern with all the engines i've been pulling apart .

the upper bearing shells on the con rods tend to be worn much more if the #4 main bearing isn't a full groove bearing .

i've also seen a lot of worn upper main bearing shell on #1 . the wear gets worse if the engine has ac on it .

[burnt_servo]

So, I should plastigauge the upper bearing shell/crankshaft, not the lower bearing. - Yes, I do have ac

quote]

you can if you want ,    but if they look worn .....  they probally are .



but the upper on the #1 main is the one that takes the most abuse . the more the drive belts squeel , the tighter people tend to crank down on the belts , causing more bearing wear on the upper shell .

also the upper shells on the rods are almost always under load , either from the piston pushing down , or the crank pushing back up if you ran it out of oil , these are the guys that will take the abuse first  .

[turbosuzi]

Blew the oil filter on the highway- now I'm getting only 25psi pressure at idle, although 75 psi above idle.  -Not as good as the 90PSI I was geting before,

What do you mean by blew the oil filter. I only ask because I had a similar experience that my oil filter expanded and I could not figure out why. The motor seized at the same time.

[squirrl22]

What happened, was the filter casing distorted- it expanded, which caused the sealing gasket to pop loose.  I'm guessing because the oil pressure on these 1.6 turbo diesels is really high-they use a different, higher volume oil pump than a regular na 1.6.  

I bought some plastigauge last night,  I'm hoping to tear into the bottom end soon.  

Any body have an idea if my wrist pin bushings are shot?

[burnt_servo]

the writs pins are splash lubricated , and should be fine ...... anything that is pressure lubricated is what will be damaged first .

[turbosuzi]

That is what happened to me. Does anyone know why the oil pump could over pressurize the filter and cause it to expand, and also why it would create a lack of oil in the crank?

[jimfoo]

Clogged oil passages in  the engine, clogged filter and faulty bypass. Those are my two main guesses.

[squirrl22]

"Does anyone know why the oil pump could over pressurize the filter and cause it to expand, and also why it would create a lack of oil in the crank?"


In my case, it wasn't the pump- it was the cheap filter used by "quick lube".  Thin filter walls may be ok for gas engines, but not for diesels. esp turbo diesels, which may run at over 100PSI, as compared to a gasser at  35PSI or less.  

Lack of oil in the crank  for me was caused by loss of oil.

This is why I now do all my own oil changes w a quality filter- I like Bosch filters, as they are very sturdy, you can buy them on sale for $5, and they are German engineered.
I also now only use Rotella 15w-40 regular oil, not synthetic.  I've read too many posts abt people developing seal leaks after switching to synthetic.

[jimfoo]

Synthetic doesn't cause leaks, it just leaks easier from already bad seals. I run it, or will after break in, because it has much better protection for the engine. The wifes 1.8T specifies synthetic.