Oil smell on Acceleration

[XfireZ51]

Here's an issue that has me a bit baffled. I don't see any oil drip BUT whenever I GET ON IT, I get a whiff of burning oil. No smoke and no smell when I am just cruising. Overnight I do have oil spotting that seems to be on the passenger side towards the front of the motor but no drip is obvious. I have checked the PCV valves and run brake cleaner fluid thru them. That seemed to loosen them up. But still getting a whiff. Also, there was some oil in the cam cover bolt recess located just ahead of the vent tube in the cam cover. I'm thinking crankcase pressure!?
BTW, speaking w Lee, he mentioned he has same issue w his 92 w 22k miles on it. The motor in my car has about 35K.

[rhipsher]

Could it be from the oil preasure sensor thats below the one up top on the passenger side. I know that if it leaks out of there that it will smoke. Cuz I remember the first time I ran mine up to 179mph that when I got back home and parked it in the drive way I noticed a little oil smoke coming from the passengers side. So I popped the hood and it was leaking a little from that oil preasure sensor. And man I'll tell you that oil was cooking after a maxed out high rpm run like that. Replaced it and never a problem ever again.

[XfireZ51]

Just pulled the plug on that one. Its dry.

[rhipsher]

This is what I would do then. Wait until its dark out and have a nice bright work light ready. Go accelerate really hard then pull over and pop the hood and shine the light on the engine to see where the smoke is coming from. If you can smell it then you should be able to see it Dom.

[VetteMed]

A thought --- if it's smoking, it's probably hitting the exhaust somewhere. You might be able to find an obvious location on the headers with a brownish burnt-oil stain, to help narrow down the location. Worth looking around with an inspection mirror...

[XfireZ51]

VetteMed,

Thanks for the thought. However, there is no smoke. I usually open the hood after a drive. The "whiff" of oil smell is over after accelerating. During cruise, no issue. Lgaff told me yesterday he has a similar issue w his 92.

[VetteMed]

VetteMed,

Thanks for the thought. However, there is no smoke. I usually open the hood after a drive. The "whiff" of oil smell is over after accelerating. During cruise, no issue. Lgaff told me yesterday he has a similar issue w his 92.

I see. I get the smell too, no smoke, but I figured it was some residual oil burning off after my recent pull of the whole exhaust system. I guess if it persists I'll look into it further. FWIW, I got a smell but no smoke when the rear diff was leaking via the pinion seal on to the exhaust. Just might want to look in that area if you don't find anything up by the engine.

[XfireZ51]

Just pulled the plug on that one. Its dry.

Just re-installed the plug. GOT U MOTHERF**KER. Here's my solution.

1. Take out side wheel house panel. Doesn't give you better access, just allows hoses to move.

2. Eat panini wife made

3. Drink 500ml of Cabernet

4. Spray arm w WD-40

5. Spray WeatherPak seal w WD-40

6. Jam arm as far as possible to grab plug.

7. Use index finger to push plug onto sensor

8. Yell I GOT U MOTHERF**KER

9. Don't listen to Paul Workman ever again.


GOT U MOTHERF**KER!

[rhipsher]

The 500ml of Cabernet was to numb the pain your hand and arm were gonna feel squeezing up in there. Probably not as bad as heat shield removal. Lol!

[sammy]

ck the oil fill cap . it has a little foam in it . this happened to my 92 .soaked the cap in gas over night let it dry and problem solved .

[Paul Workman]

9. Don't listen to Paul Workman ever again.


GOT U MOTHERF**KER!

:-({|= Aw...You want a little cheese to go with that whine? (I toadja I wuz gonna bring my special tool w/ me today - purchased just for that SOB!) Of course you knew that sensor wasn't leaking before you inspected it, but you just wanted to experience the pleasure of reinstalling that "MOTHERF**KER!" once you had it apart...I know you! :sign10: Sounds like you need a little "there-there" :icon_pai: Have some more whine...er...wine and be happy you don't have to pull the oil filter housing!

My solution to that connector was a pair of foot-long hemostats (from Harbor Freight) and a long shanked screwdriver. Grabbed the connector with the hemostats and lined it up, and with the screwdriver I pushed up on the bottom of the connector until - "CLICK"! Ahhhh. What a welcome sound!!:dancing

Spraying your hand with WD-40, huh? (Yeah, but is that the hand you used to reach the connector??) Pete the Greek loves KY, for some reason - even has "KY" on his license plate, if you think I'm kidding! It must be some kind of ritual you "Mediterranean" bred people take pleasure in...But, I'll leave it to youz guyz to go there...I want NO part of that!:jawdrop:

[tomtom72]

Dom, I've been thinking about this issue and the burning part has me leaning to a leak either at the dip stick tube seal, or that cam cover vent tube where the cam cover bolt is wet.

I would seem logical that crankcase pressure has some connection as per your recount of what's happening. I can't see the CCV box cover or the two hoses as an issue as that ends up at the right rear of the oil pan. I suppose it could blow back on the exhaust? I'm trying to find a more direct route from the leak point to the exhaust system to yield your burnt oil odor.

:cheers:
Tom

[XfireZ51]

:-({|= Aw...You want a little cheese to go with that whine? (I toadja I wuz gonna bring my special tool w/ me today - purchased just for that SOB!) Of course you knew that sensor wasn't leaking before you inspected it, but you just wanted to experience the pleasure of reinstalling that "MOTHERF**KER!" once you had it apart...I know you! :sign10: Sounds like you need a little "there-there" :icon_pai: Have some more whine...er...wine and be happy you don't have to pull the oil filter housing!

My solution to that connector was a pair of foot-long hemostats (from Harbor Freight) and a long shanked screwdriver. Grabbed the connector with the hemostats and lined it up, and with the screwdriver I pushed up on the bottom of the connector until - "CLICK"! Ahhhh. What a welcome sound!!:dancing
Spraying your hand with WD-40, huh? (Yeah, but is that the hand you used to reach the connector??) Pete the Greek loves KY, for some reason - even has "KY" on his license plate, if you think I'm kidding! It must be some kind of ritual you "Mediterranean" bred people take pleasure in...But, I'll leave it to youz guyz to go there...I want NO part of that!:jawdrop:


Paul,


You dropped your soap.

[XfireZ51]

Tom,

Both are on pass. side. However, when I run my hand on the oil pan, there's an oil film there starting from the front of the sump portion. The vent tube was slightly cocked and I have fixed that. Doesn't seem to be any additional oil pooling at that cam cover bolt. I'll clean things up and see if get any fresh tracks after a drive around.

[FU]

You dropped your soap.

Don't try and pick that soap up when Pete's there.

[tomtom72]

Dom, the crank sensor is not leaking from it's o-ring is it? I just thought of that one.:o

These types of quirks can be maddening to track down.....good hunting on this one Bro! It took me quite a few tries to locate the source of an oil leak on my friend's motor.....eventually we tracked it down, but it took us a lot of looking to find the source. It was a good thing his motor was very clean as it made it easy to back trace the leaks.

:cheers:
Tom

[XfireZ51]

Now that 474 is at it's new home, I'm able to park 458 in my garage. I took it out for another spin yesterday. Got on it, got a brief whiff again. However, got on it a few more times (motor feels very strong w some timing changes I've made.) and didn't smell anything further. I have a piece of white peg under it know which won't absorb the oil like cardboard and shows up oil spotting more easily. Again, small amount on passenger side and. it appears to be in horizontal line at rear of lower control arm. Also in line w oil dipstick although I don't think that explains oil film on front right corner of oil pan sump area. I may bring car to Pete's, if he has time and put on his lift for a quick look see.
Also w garage now available, I'll be pulling upper and lower control arms to replace bushings (w poly), lower ball joints, and shocks.

[rhipsher]

Are you going to go with poly or rubber?

[XfireZ51]

This all started when Marc H. recommended poly bushings for the coilover shocks. I found a good source of Energy Suspension bushings and bought the control arm kit since I need to also replace lower ball joints and will be dismantling front suspension anyway. At 112k miles, I fgure the bushings need some freshening.

[XfireZ51]

OK. Well I was able to get the car up on jackstands. Its been sitting in the garage with a piece of white peg board sitting underneath. This makes it easy to spot the leak and it doesn't absorb into the pegboard. I can see exactly what part of the undercarriage the oil is coming from.
And the winner is:
Passenger side front oil pan stud. Its the top right hand corner of the motor. Its a stud and nut setup.

[Paul Workman]

OK. Well I was able to get the car up on jackstands. Its been sitting in the garage with a piece of white peg board sitting underneath. This makes it easy to spot the leak and it doesn't absorb into the pegboard. I can see exactly what part of the undercarriage the oil is coming from.
And the winner is:
Passenger side front oil pan stud. Its the top right hand corner of the motor. Its a stud and nut setup.

As my grandma used to say, "You shoulda looked there first!":p

P.

[tomtom72]

:handshak:=D>

:mrgreen: no more oil leaks are a good thing!

[XfireZ51]

Well now the question is how to seal it. Not sure whether it's loose or if the stud hole is not sealed at the pan/block.

[rhipsher]

Oh man! Is that all it was? I was hoping for something more exciting. Your no fun Dom.:dontknow:

[FU]

Pull the stud out... clean it .. seal the stud threads .. then put it back in .

Pull it out .. then put it back in. No one listens to the guy !

[A26B]

Well now the question is how to seal it. Not sure whether it's loose or if the stud hole is not sealed at the pan/block.


Surely it must be loose. The pan gasket bolt holes have gasket material 360deg around every bolt hole. If all the rest of the bolts are tight, I would think the whole stud could be removed and still not leak. If that's what is leaking, then there are probably more loose bolts than just that one.

The dipstick tube seal is real close to that location & a leak could conceivably follow the pan rail & drip off elsewhere.

Please let us know what you find.

[XfireZ51]

Thanks for the suggestions guys. I'll be jumping
under the car later this morning and give you an update of what I found. Hoping it's just a loose nut. This corner of the oil pan had been damaged in the wreck. When we pulled the motor we found that the stud had been nicked and bent slightly producing a crack at the stud hole. Al did a great job welding it. So I'm pretty sure that's not the issue. Keep you posted.

[XfireZ51]

Got under the car this morning and it looks like no joy. The stud I am looking at is a stud because it has a double nut setup. The oil pan nut is hidden under the heat shield for the O2 sensor connector. So I basically sprayed brake cleaner to clean things up and tightened the shield nut. I'm hoping that part of the issue may have been caused by pressurization of the crankcase due to a sticky PCV valve. The oil loss appears to have lessened but I'm not holding my breath. We'll see.
An interim solution may be to support the motor and then remove the motor mount support bracing on both sides. That looks like it would provide access to all the pan bolts including the second heat shield nut currently covered by the brace.
Anyone here ever access the oil pan this way?

[A26B]

Dom,
No need to support the engine. You can remove both of the K members without problem, and get to all of the pan bolts. The K members do not support the engine.

I doubt tightening the shield nut will do much for the stud, hope so though. The cat shields aren't too hard to remove..... definitely not like the manifold heat shields.

[XfireZ51]

Dom,
No need to support the engine. You can remove both of the K members without problem, and get to all of the pan bolts. The K members do not support the engine.

I doubt tightening the shield nut will do much for the stud, hope so though. The cat shields aren't too hard to remove..... definitely not like the manifold heat shields.

Jerry,

That's great information. But aren't the motor mounts bolted to the K members? Not doubting, just want to understand the setup. If I can do this, I guess I can first try tightening the stud nut and see if that works. I only need to remove the passenger side K brace.
If it doesn't, then I'll order another pan gasket and install it at the next oil change later this year.

[tccrab]

K Members only look like they support the engine, when in fact they do not.
They can be removed with no detrimental effects.
Removing them is the only easy way to get to the front pan bolts.

TomC
'Crabs

[A26B]

The Mtr mounts sit on a pad welded to the frame & the k-members bolt underneath the pad, to the motor mount stud.

http://i190.photobucket.com/albums/z224/A26B/Enginebay2.jpg

[XfireZ51]

Outstanding! I guess I didn't give those GM guys enough credit for allowing oi pan removal without pulling the motor or need for supporting it somehow.Thanks guys.=D>

[4-cam]

I just did this Thursday night. Replace the O2 sensors while I was tightening the pan bolts. The left side O2 sensor connnector was a bitch to get at. 3 front pan bolts were loose causing my oil leak. Removing the K braces were much easier than I thought.

[Paul Workman]

K Members only look like they support the engine, when in fact they do not.
They can be removed with no detrimental effects.
Removing them is the only easy way to get to the front pan bolts.

TomC
'Crabs

I've had my motor in and out a couple 3 times, but never had a need to remove the K braces - just assumed the motor was supported by them...Learn something every day 'bout these beasts!

P.

[XfireZ51]

Just finished buttoning things up. The top bolt of the K Brace located at the frame side rail was blocked by the header tube. I was able to loosen it up enough to swing K Brace away from pan.
Heat shield was bent but no big deal. Pulled stud out and cleaned it, put a little black RTV to help with stud sealing. I'll
take it out in a bit and see if that helped. Otherwise, I'll be ordering a new pan gasket from Jerry. I would have taken the car to my local LT-5 for warranty work but his voicemail message says he's in Greece! ;)

[XfireZ51]

Took the car for a run yesterday after closing the oil pan up. Drove for about 45min including some high rpm gear change. Running well even in hot temps.
Came home parked car over white peg board. Its now 24 hours since motor shutoff. NO OIL! YAY!
I will say that I still got that oil smell when I hammered the gas the first time. Doesn't seem
to happen after that or at cruise.

[XfireZ51]

It's been 3 days since finishing work on oil pan stud. O had am opportunity to take car out again on a run to Melrose T-top in Cortland. Drove about 75mi in some heat. No oil. I still get a bit of a whiff when I hammer the gas. I pulled plugs this weekend and saw no evidence of oil. Plugs looked in
very good shape. Each plug appeared to be burning very close with a light gray
insulator.

[ittlfly]

It's been 3 days since finishing work on oil pan stud. O had am opportunity to take car out again on a run to Melrose T-top in Cortland. Drove about 75mi in some heat. No oil. I still get a bit of a whiff when I hammer the gas. I pulled plugs this weekend and saw no evidence of oil. Plugs looked in
very good shape. Each plug appeared to be burning very close with a light gray
insulator.

You might check the area of the cam positioning sensor for oil (on the drivers side). Mine was leaking at the O ring seal and dripping onto the exh. manifold. Sort of an ''easy'' fix.

[XfireZ51]

You might check the area of the cam positioning sensor for oil (on the drivers side). Mine was leaking at the O ring seal and dripping onto the exh. manifold. Sort of an ''easy'' fix.

The drip I had previously seen was on the passenger side. Worked on that this weekend and no sign of oil either on the floor or on bottom of pan. The cam sensor was recently removed and resealed with the cam and heads upgrade that was done earlier this year. There no smoke coming from the engine bay when idling or even after having beeen driven hard. As I stated in a previous post, I also don't see any evidence of oil in the cylinders.
Plugs are dry and grayish.

[ittlfly]

Yep, if I re- read your post I would hve seen the leak was on the pass side....sorry.