Author Topic: low oil pressure (Read 5020 times)

82caddy td · « **on:** April 09, 2005, 12:07:52 pm »

I have an 82 caddy with a 91 td engine. I just redid the head and new rings and rod bearings. The problem I'm having is that the oil pressure seems to be really low. When the engine is cold it reads about 4bars max and as it warms up it drops. When the engine is normal operating temp. it reads about 1bar sometimes it'll go even lower. Never had it drop to zero yet. I also had the oil light and buzzer come on after driving on the highway for about half an hour and getting off. I just replaced the oil pump also without any change. Just wondering if anybody has experienced this situation ?

vwmike · « **Reply #1 on:** April 09, 2005, 01:38:29 pm »

Did you change your intermediate bearings? Sometimes those can wear and be a source of low oil pressure.

82caddy td · « **Reply #2 on:** April 09, 2005, 07:38:01 pm »

vwmike thanks for your reply. I have not changed the intermediate bearing. Do you know if there is two or one bearings on the shaft,how much pressure can be lost there?

chrissev · « **Reply #3 on:** April 10, 2005, 01:56:26 pm »

Quote from: "82caddy td"

I have an 82 caddy with a 91 td engine. I just redid the head and new rings and rod bearings. The problem I'm having is that the oil pressure seems to be really low. When the engine is cold it reads about 4bars max and as it warms up it drops. When the engine is normal operating temp. it reads about 1bar sometimes it'll go even lower. Never had it drop to zero yet. I also had the oil light and buzzer come on after driving on the highway for about half an hour and getting off. I just replaced the oil pump also without any change. Just wondering if anybody has experienced this situation ?

query: what was the oil pressure like before you "rebuilt" the engine? Perhaps you've forgotten to do something during the re assembly process

vwmike · « **Reply #4 on:** April 10, 2005, 02:44:14 pm »

Quote from: "82caddy td"

vwmike thanks for your reply. I have not changed the intermediate bearing. Do you know if there is two or one bearings on the shaft,how much pressure can be lost there?

There are 2 bearings on the shaft, but the engine has to be removed before you can change them. I don't think that's what you wanted to hear. But chrissev has a good point, you didn't forget to put your squirters back in or something, did you?

82caddy td · « **Reply #5 on:** April 10, 2005, 11:39:58 pm »

I never had a pressure guage installed before the rebuild so I'm not too sure. I did however check it with a guage at the head just before I dismantled the engine and at idle after warm up it was about 1 bar. So in reality it did'nt really change any. I never removed the squirters or the main bearings,just the pulled the pistons to change the rings and rod bearings.I'm also using 15w40 oil,just wondering if that's thick enough or should I use something heavier? The engine runs strong,no lifter noises or any other funny noises.

chrissev · « **Reply #6 on:** April 11, 2005, 01:45:26 pm »

Quote from: "82caddy td"

I never had a pressure guage installed before the rebuild so I'm not too sure. I did however check it with a guage at the head just before I dismantled the engine and at idle after warm up it was about 1 bar. So in reality it did'nt really change any. I never removed the squirters or the main bearings,just the pulled the pistons to change the rings and rod bearings.I'm also using 15w40 oil,just wondering if that's thick enough or should I use something heavier? The engine runs strong,no lifter noises or any other funny noises.

15/40 is actually pretty thick. Could be main/intermediate shaft bearing problems, or a bad pump.

Rat407 · « **Reply #7 on:** April 12, 2005, 05:45:17 am »

Well to make things worse, I completely rebuilt my 1.6 TD out of my 91 Jetta and after I got it up and running I had low oil pressure. At the head with a good mechanical gage I get 20 psi on start up running 15/40 oil and when it warms up, or just a simple 3 mile drive down the road the gage sits on Zero. I get 10 psi at hot idle at the oil filter housing and 20psi at highway speed. I replaced all the bearings and they all are to the specifications that the Bentley shows. It is all new, rod, main bearings and even the intermediate shaft bearings. New oil pump and the oil squirters are installed. The engine was hot tanked. It is a complete fresh rebuild but with super low oil pressure. It was low before I started and the engine had 162k miles on it then. I since put 5k miles on the new rebuild and have torn back into it due to high oil consumptions, one qt of oil to 400 miles of driving. For some reason I have high blow by so I'm pulling the pistons out to see what the problem is. My compression was great at 460psi in each cylinder. Don't have a clue as to why the low oil pressure. The head was getting plenty of oil, the leaks around the valve cover can atest to that. :shock: When I went to torque the head it was soaked under there. So I'm getting flow, just not pressure. I'm wondering if my oil pump relief valve didn't slam open and stick there from initial start up. Going to check that tonight and try to get the pistons out as well. The head is at the machine shop, only because during all this my cam sprocket slipped on the cam shaft and my timing was off so I had one valve hitting the #2 piston. No other damage that I can see so the head is in getting checked over. If anyone can find the answer to the low oil pressure that shows up on this forum and one other forum every so often, they would be a rich and all powerfull individual. So far I have not been able to find a reason for it.

82caddy td · « **Reply #8 on:** June 22, 2007, 06:50:02 pm »

Well it lasted this long and just the other day my cam broke.I figure the low oil pressure was due to the intermediate shaft bearings.Now I just installed an AAZ from a 96 jetta. Used my old turbo and the serpentine belt setup.Oh and it goes like stink too.Have one issue though as I have an oil temp gauge setup my oil temp is verrrrry high,like 130C most of the time.Just installed a different oil temp. sender so I'll see what it's like now.