Lanny Curlett

HI,

I have an 83 944 race car with a '93 968 motor in it. I blew the oil pan gasket and while I was having that replaced I had the tech replace the rod bearings as well. During the course of all that the tech discovered that the oil pick up tube was cracked. I have had noisy lifters in the car. My question is, what effects will the cracked tube have had? I'm having it replaced with new but wonder if the noisy lifters are related to the tube and what other effects it would have had. Anybody?

TIA,

Lanny

RajDatta

Lanny, typical symptoms of cracked tube are inconsitent oil pressure and air in the system. The symptoms can be a noisy cam chain tensioner, which is probably what you were hearing. Pickup tubes usually crack from lower balance shaft being out of alignment. Since our cars are huge 4 cylinders, the effects from unbalanced lower shafts (harmonics) are much worse than they would be on a smaller displacement car.
Regards.
Raj

mikew968

Consider yourself luck ythe oil tube didn't fail altogether.

Mike

Renalicious

When you say inconsistent oil pressure, is there a specific range or all around? Over the past few months I've started noticing my lifters more, but my oil pressure has been pretty consistent. Then again, I do have old oil. I got the pan gasket changed last year and they didn't mention anything looking out of the ordinary in the crank case.

However I do also have a significant oil leak coming from the rear main seals (which I'm getting fixed tomorrow finally). So I'm hoping all the lifter ticking is due to the old oil and bad pressure from that leak.

I know it's a large job to get the oil pan off the car (from what the old mechanic told me), but after that getting to the pick up tube should be simple, right?

RajDatta

Yes, getting to the oil pickup tube is quite simple once you have the pan off. As far as the oil pressure, the guage will not give you the tell tale. It will be more that the cam chain tensioner will be sucking air from the cracked tube and the chain will make noise.
How many miles on your car Renalicious. Hydraulic lifter do get weak over time. Sometimes they get gunked up from old oil/contaminants.
Raj

Renalicious

Mine is just over 130K miles

RajDatta

Ren, it could be that the lifters are just old and tired. Changing your oil will definitely help but if the ticking doesn't go away, you might have some weak lifters. Also, the injectors tick as well. Make sure you use some way to eliminate that its not the injectors that you are hearing.
Raj

Renalicious

Ok, once I get the car back with some fresh oil I'll take it out and take a listen. It might be as simple as old thin oil.

Renalicious

Yep, looks like the majority of the knocking was due to old thin oil. After listening carefully I can isolate what is injector ticking, and what isn't, so the enging now sounds pretty normal afterall