North American Turbocoupe Organization



Low Oil Pressure
cdkes Offline
Junior Member
#1
I bought an '88 5 speed not too long ago and she needs a lot of work. Just a few days ago I replaced the valve cover gasket and now I'm getting abnormally low oil pressure readings (very low end of normal). I blasted the hell out of the IAC and the EGR valve with carb cleaner during the gasket swap as well. The car is leaking a small amount of oil from somewhere on the driver's side but I haven't pinpointed where yet. Spark plugs and wires are at most two months old, the oil was changed a couple hundred miles ago. The car definately doesn't pull as strong as it did before the swap - seems like there's a boost leak somewhere. Gillis bypass valve with four threads out and less than 15 psi boost. Any ideas on what's going on? It doesn't seem to be burning oil (can't smell it and only white, sweet-smelling smoke out of the exhaust, not blue) but I just had to add two quarts of oil today. [Image: frown.gif]
Reply

JT Offline
Posting Freak
#2
The back driver's side of the valve cover is where the oil pressure sending unit is, as well as the turbo feed line. Two common leak points.

Also, what type of gasket did you use? The Ford ones are the best, as the cheaper ones tend to leak. i've had it happen, and so have others on this forum.

i'm not dismissing your oil pressure concerns, as i wouldn't take something like that too lightly. However, the stock gauges are not very accurate. If you have an oil pressure concern, it is best to check with a better gauge.
Reply

cdkes Offline
Junior Member
#3
Thanks for the reply, I'll be checking those tomorrow evening. I used the blue rubber Felpro gasket and just noticed something a few minutes ago - it's not situated well over the cam timing tower, however it doesn't seem to leak oil from there when the engine is running. Could this be the/a cause?

Also, the gauge read in the middle of normal (not 100% steady, but pretty close) before.
Reply

Pete D Offline
Administrator
#4
Quote: it's not situated well over the cam timing tower, however it doesn't seem to leak oil from there when the engine is running. Could this be the/a cause?

This is not the cause of the low oil pressure reading if that is what you mean. Assuming you have enough oil in it, the low reading may be die to a failing oil pressure sending unit. Sometimes when they start to fail they read progrssively lower.

" Do all your gauges read low? If so, the instrument voltage regulator is probably bad. If just the oil gauge reads low, check the connection to the sending unit to be sure it is tight and not corroded. If still low, try replacing the sensor, as they are known to go bad. You can get one from Ford for about $20. BTW, it seems to be normal that the gauge reads low on hot startup, probably due to the sender heat soaking and its resistance going up. It might be a good idea to use a mechanical pressure gauge to see what the actual pressure is. Ford spec is 40 to 60 psi at 2000 RPM, with oil hot." Jeff K, earlier post, http://natomessageboard.com/Forum1/HTML/000327.html

Tell us more about the white sweet smelling smoke for the exhaust. Have you checked your coolant level, looked for oil in the coolant or coolant in the oil. It sounds like you might have a blown head gasket or, worse, a cracked head. Besides the above symptoms, do a full compression test. Details for that are here: http://www.turbotbird.com/techinfo/Compr...n_Test.htm
Pete Dunham


Reply

JT Offline
Posting Freak
#5
Pete is right. It is possible that the oil pressure sending unit is failing, causing the gauge to read lower and lower.

By the way, the gasket can be a bit tough getting properly on (without slipping) in that spot. It is a common leak spot.
Reply

cdkes Offline
Junior Member
#6
Pete - thanks for the reply. I did a search but I didn't notice anything about just the oil pressure unit dying. The coolant gauge reads low but fuel seems fine as does the battery gauge. This indicates to me that the instrument cluster is functioning alright, is that correct?

I will definately check the oil pressure sending unit's connection tomorrow as well. I think I'll just take it apart again - remove IC and upper intake to reseat valve cover gasket, that should give me more room to get at the sending unit anyways, as well as let me check the compression before I take the intake off (thank you for the guide - didn't even think about checking it, silly me).

The white exhaust smoke seems to be a recent change, I didn't notice it when I bought the car. For a while the boost was way too high, so that may have blown it. Oil and coolant both seem separate and I just added coolant the other day (low when I bought it, seemed to stay steady but that's just eyeballing it from the top). Luckily, the car came with a spare head (valves and all) - I believe the previous owner had plans to do a carb conversion (as it also came with a Holley carb in the trunk [Image: smile.gif] ). Would head likely be the same as what is on there now? It looks the same but I wouldn't know how to tell the difference.

Thanks again.
Reply

Matt S Offline
Posting Freak
#7
Like Pete said just the valve cover gasket, and anything else intake won't affect your *real* oil pressure. I suspect that with you bumping all around in there you loosened the pressure sending unit connection as suggested. Double check that post connection on the silver cylinder next/under the egr.
The amp meter has never been known to move [Image: biggrin.gif] . If your coolant, gas and oil all read low at the same time. Then it's the notorious IVR. Sometimes I could see them drop all together. Most of us get aftermarket gauges since the vague ones suck anyway.
Sold it Sad*
Reply

JT Offline
Posting Freak
#8
The AMP gauge is on a totally different circuit from the oil pressure, fuel level, and engine temperature gauge. The IVR issues do not apply to the AMP gauge.
Reply

Pete D Offline
Administrator
#9
Quote:but fuel seems fine as does the battery gauge. This indicates to me that the instrument cluster is functioning alright, is that correct?

There are only 2 or 3 people here that claim to have a functioning amp gauges. I thought I saw the needle move once on one of mine but I blinked so??? [Image: biggrin.gif]

The thing with the oil pressure, temp and gas gauges is they move up (or down) in unison if it is the IRV problem.

A turbo head will have "D" shaped combustion chambers. The NA heads have a heart shaped combustion chamber. see the two pics
Pete Dunham


Reply





Users browsing this thread:
1 Guest(s)



Theme © iAndrew 2018 - Software MyBB