More smoking issues...

[yousaidpoo]

My engine is smoking more than a nervous chain smoker. It looks/smells like oil smoke. The oil I'm running is 10w30 Castrol GTX.

I took the car out for a drive after getting tires, and it handles really well on 195/60 Goodyear Eagle GT-HRs. Thats pretty much it for the good news.

After the engine got up to a normal operating temp, things started going wrong, in this sequence:
1) A little bit of smoke coming out from under the engine. I had a little oil spilled onto the headers so i figured that it was the oil that i wasnt able to get off burning off. No big deal.
2)Engine is idling higher now that it is warm. Pretty sure that's a bad temp sensor. This is when i turn around.
3) Oil warning light comes on, but only when the engine is pulling less than 1500 rpm. This is when i decide to baby the car back home (2-3 miles)
4) Pulled into my driveway and there was smoke more or less billowing out from the car, and coming out from the engine lid.

So my question is, whats going on (besides the bad temp sensor, which i will replace ASAP)? And could a bad temp sensor cause all these problems, since it effects fuel metering and therefore mixture?

I am frustrated.

[lapuwali]

I'd run 20w50 instead of 10w30 in a T4 unless it's a lot colder than I'd expect where you are.

[yousaidpoo]

yea i'll probably do that then, because it was 90 and humid today

[Dave at Pelican Parts]

Sounds like you've got a good-sized leak. Buy a case of brake cleaner and get in there and start cleaning. Re-fill the oil (bet a lot of it is gone now!) and start the engine. Let it run for a minute or so and then turn it off and start checking for oil. The leaks are usually at the furthest forward and highest spot you can find oil.

Might be an oil gallery plug at the one end of the engine or the other. When they blow out, you usually dump all of the oil out, so it may still be there but leaking a lot. Also check by the oil cooler, the oil filter, the oil pressure sender...

Oh, and the cover for the oil pressure control piston, right Jason??

--DD

[fatlando]

my 75 914 2.0 is doing the same thing. here in missouri its in the 90's, and i'm using 5w30.

i'm going to try the 20w50 and see what happens.

did the change help you?

[yousaidpoo]

didnt have time to change the oil today- thats on the list for tomorrow. I did, however, check the oil level and its right where it needs to be, which is odd. Before i change it though, i'm going to run it in my garage until it starts smoking, then look for oil on the engine/floor/wherever. I'm also going to do some really extensive cleaning. To make sure there isn't any oil on the engine anywhere else.

So I guess the big question is would issues with the temp sensor (not the cht sensor) and/or issues with the auxilary air regulator cause the car to smoke?

[lmcchesney]

The Temp Sensor and AAR adjust the enrichment of the engine. An engine too rich will produce some smoke out the end of the exhaust, but now oil on the headers. From your information, it sounds more like an oil leak, to be defined as David has discribed.
L. McC

[Dave at Pelican Parts]

Which temp sensor? The CHT has a major effect on the mixture, but you said it wasn't that one. The IAT (intake air temp) sensor has a relatively minor effect on mixture. The AAR has pretty much zero effect on the mixture; it's just there to provide a high idle when the engine is cold.

Smoke coming out of the engine bay is oil that has dripped onto the heat exchangers. About 98% guaranteed. Find the oil leak and you should be able to (eventually) stop the smoke.

The oil pressure light coming on is a real concern. If your sender is hooked up correctly, it may be failing. Probably a good time to replace it. The senders can also leak...

--DD

[Jason Porter]

Originally posted by Dave at Pelican Parts
Might be an oil gallery plug at the one end of the engine or the other. When they blow out, you usually dump all of the oil out, so it may still be there but leaking a lot. Also check by the oil cooler, the oil filter, the oil pressure sender...

Oh, and the cover for the oil pressure control piston, right Jason??

--DD

Yuck it up buddy! LOL, I swear. God smiled on me for sure.

It's got more Yamabond on it than a racetrack full of crotchrockets. It'll never leak again. In fact, I don't know if I'll ever be able to get it out.

Cheap fixes are nice. If you can't find the leak's origin, i.e. it's buried under engine tin, plenum, whatever; then you may want to do inexpensive, preventative fixes.

I once had an oil leak, and it was high and frontal. I couldn't find it. So, I replaced the oil fill gasket, pressure switch, and oil cooler seals. The leak was gone. 3 days later, After a lot of miles, I reved it a little too high, and dropped a valve seat. But for around 25 bucks, and 3 hours of cursing at those oil cooler seals, I ditched the leak.