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Oil Pressure

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Printed on: 20 Aug 2014

Topic:


Topic author: neadles
Subject: Oil Pressure
Posted on: 16 Jul 2006 7:59:11 PM
Message:

Hi I was wandering if anybody has experienced oil pressure problems ?
I have a 1990 Vn V6 that has done 300,000km .It runs quiet and doesnt get hot .About a couple of weeks ago I noticed after it got to its running temp and when I put into drive the oil light would flash .
After trying to eliminate as many other possibilities as I could I finaly put a oil pressure gauge on it to day .The max it would go to cold was 25PSI and at idle about 10PSI so somethings not right .
I've checked the pressure reg and bypass valves and they're fine .
The only other thing I can think of is Oil pump or pick up .
So has anybody experienced anything like this ?While I've had it I've always done regular oil changes and I havent seen any metal or grit come out with the oil .I just did a oil change into a white container to see if anything was in the oil ,but it looked good .
So any ideas .
Brian

Replies:


Reply author: mouce
Replied on: 16 Jul 2006 9:05:46 PM
Message:

Could be the pickup in the sump, it's not uncommon for them to get covered by some sludge and have problems picking up the oil. In fact after 300,000km, it's a good chance that it's your problem, but I can't be certain.

Does it seem to be burning any more oil than normal? Try a compression test on the engine, could be burnt out rings (hope not), but a compression test should rule that out.


Reply author: neadles
Replied on: 16 Jul 2006 11:30:15 PM
Message:

quote:
Originally posted by mouce

Could be the pickup in the sump, it's not uncommon for them to get covered by some sludge and have problems picking up the oil. In fact after 300,000km, it's a good chance that it's your problem, but I can't be certain.

Does it seem to be burning any more oil than normal? Try a compression test on the engine, could be burnt out rings (hope not), but a compression test should rule that out.


Reply author: neadles
Replied on: 16 Jul 2006 11:36:57 PM
Message:

I've tried using a compreser to blow back down tube for pick up and seamed to be clear .Also motor doesnt use oil .The only thing I can think of is oil pump but I cant think of why.The other thing I can think of is that the oil pick up has cracked somewhere.


Reply author: mouce
Replied on: 17 Jul 2006 10:40:28 AM
Message:

I just went digging through my Gregory's manual and found a large list of things which could cause low oil pressure. The following sort of stood out as potential causes:

2) Thin or diluted oil (when you do an oil change, what sort of oil do you use?)
3) Blocked oil filter (when you do an oil change, do you always change the filter?)
4) Oil pump relief valve stuck or spring broken (got no idea where it is, but it might be worth investigating that one further).
6) Excessive bearing clearance (in other words, the bearings have worn away and are providing little to no back pressure for the oil)

The other option is a worn oil pump, but I don't know any easy way to check that other than stripping the oil pump.


Reply author: neadles
Replied on: 17 Jul 2006 11:01:14 AM
Message:

I've changed the oil and filter (did that first)I used a BP 20w50 ,I wouldnt think that would be to thin .
The oil pump relief valve is behind the oil filter in the adapter plate ,and I've checked that .The spring is the right length (66.3mm)and the piston doesnt stick.
I thought about worn or spun big ends but the motor is to quiet ,the only thing I can think of is worn oil pump or maybe the gasket on the timing cover is leaking .The oil pick up travels through the block into the timing cover so a leak here might cause problems .I'm going to pull the timing cover off this arvo .


Reply author: mouce
Replied on: 17 Jul 2006 3:30:10 PM
Message:

The BP oil isn't the best. On young motors my oil of choice is Magnetec, on any motor that's done more than about 150,000km, Penrite HPR15 or HPR30 (depending on how badly the rear main seal leaks). Even after 10000km it still has a nice honey colour in there, everything else I've ever tried was burned black by about 8000km.

I do the filter every time the oil gets done. Some people do it every second time, but I look at it this way: it only costs a couple of dollars, it's cheaper than having dirty oil kill the engine.

Have fun with the timing cover!


Reply author: neadles
Replied on: 23 Jul 2006 10:07:42 PM
Message:

So whats wrong with BP oils??? What a pain in the ass ,every time you menchine oil brands on these forums out comes the crap .If you engine oil is still clean after 10,000km's your engine is F*.$&ed .Penrite is Ok but only if changed regulary ,leave it any longer and you get a big varnish biuld up and noisy lifters .If your oils gone black by 8,000km's thats normal .10,000km yeah right ,Magnetic sounds like one of those reclaimed sump oils ,wouldnt use it to lube my chain saw bar .


Reply author: mouce
Replied on: 23 Jul 2006 10:11:38 PM
Message:

I'm not saying that BP oils are crap, I'm just saying that in what I've come across...they aren't the best oil to use in th Buick V6 motor.

BTW: I never said that it was still 'clean' after 10,000km...I know that that would be a bad sign, I'm just saying that it's not burned completely black like a lot of the other oils.

Anyway...'nuf of that...how'd you go with the timing cover?


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