97 STS smokes after heats up

[coolj940]

I have a 97 STS with 77k on it. Everything works and the car runs fine. When it reaches normal temp (about 10mins) it starts to smoke on accel, not while just cruising. Check engine light is on as well. Any suggestions?

A gm tech told me that it sounded like it could be the intake gasket. I'm going to be fixing it myself and would like to try and figure out what it is. I don't think it's a head gasket because it doesn't over heat, Oil looks fine, however it is low. Haven't had a chance to check coolant yet..

Please let me know what I could look for or do to try and diagnose the problem.

PS: just checked coolant and it looks like oil is getting into the coolant (milk shake)

[BodybyFisher]

I have a 97 STS with 77k on it. Everything works and the car runs fine. When it reaches normal temp (about 10mins) it starts to smoke on accel, not while just cruising. Check engine light is on as well. Any suggestions?

A gm tech told me that it sounded like it could be the intake gasket. I'm going to be fixing it myself and would like to try and figure out what it is. I don't think it's a head gasket because it doesn't over heat, Oil looks fine, however it is low. Haven't had a chance to check coolant yet..

Please let me know what I could look for or do to try and diagnose the problem.

PS: just checked coolant and it looks like oil is getting into the coolant (milk shake)

Go to the top of this page click HOW TO, go to READING DTC CODES, and follow the instructions on how to read the codes, read the codes, and post them here.

Secondly, your GM TECH appears to be saying that the smoke is being caused by bad intake manifold gaskets?, forget that, he is mistaken, NO OIL passes through the INTAKE MANIFOLD AT ALL in the Northstar.

Third, you talk about MILK SHAKE coolant, change it immediately. You could be seeing the result of the cooling supplement tablets in the cooling systme. Change the coolant and DO NOT forget to add the cooling system tablets.

Change the OIL and filter immediately and use a good grade of 10W30, maybe your oil is diluited with fuel from a bad FPR.

Once you figure out the codes, change the coolant and oil, we can tell you how to do the WOT procedure, you may need to loosen up the rings and reseat them, the engine likes to be beat, driving it like an old lady will cause oil consumption

[KHE]

If you have verified that it is oil in the coolant, the cause could be the result of a bad oil cooler line in the radiator. Keep an eye on it after you drain and refill the coolant. You may need to change the radiator.

[BodybyFisher]

If you have verified that it is oil in the coolant, the cause could be the result of a bad oil cooler line in the radiator. Keep an eye on it after you drain and refill the coolant. You may need to change the radiator.

Good Point Kevin.

[coolj940]

First off, the coolant is brown dextron stuff, my father whom is a mechanic said it's suppose to look like a muddy color.

Well we took the car for a 75 mile drive last night, it smoked randomly on acceleration, but not at all consistent, Got it home and I jumped in the Eldorado and followed my wife, she went wot 15-80 it looked like dark white/gray smoke and just smelt like exhaust, possible running lean...

We took it for about a 35 mile spin tonight and it didn't smoke at all, had codes pulled as well....

here is what they were.

p0137-h025 circuit Low Voltage Bank 1 Sensor 2

p0147-h025 heater performance bank 1 sensor 3

p0154-h025 circuit insufficient activity bank 2 sensor 1

p0300-engine misfire detected

p0404-egr open position performance

p0405-position sensor circuit low voltage

po1139-ho25 insufficient switching bank 1 sensor 2

p1153-h025 insufficient switching bank 2 sensor 1

Now I do realize some of these codes could be from past problems, correct?

[coolj940]

I was just wondering if anyone had anymore advice since I found out the codes.....

I'm leaning towards changing the EGR and then the oil...

Somebody mentioned that a bad egr would cause fuel to get into the oil????

First off, the coolant is brown dextron stuff, my father whom is a mechanic said it's suppose to look like a muddy color.

Well we took the car for a 75 mile drive last night, it smoked randomly on acceleration, but not at all consistent, Got it home and I jumped in the Eldorado and followed my wife, she went wot 15-80 it looked like dark white/gray smoke and just smelt like exhaust, possible running lean...

We took it for about a 35 mile spin tonight and it didn't smoke at all, had codes pulled as well....

here is what they were.

p0137-h025 circuit Low Voltage Bank 1 Sensor 2

p0147-h025 heater performance bank 1 sensor 3

p0154-h025 circuit insufficient activity bank 2 sensor 1

p0300-engine misfire detected

p0404-egr open position performance

p0405-position sensor circuit low voltage

po1139-ho25 insufficient switching bank 1 sensor 2

p1153-h025 insufficient switching bank 2 sensor 1

Now I do realize some of these codes could be from past problems, correct?

[Texas Jim]

here is what they were.

p0137-h025 circuit Low Voltage Bank 1 Sensor 2

p0147-h025 heater performance bank 1 sensor 3

p0154-h025 circuit insufficient activity bank 2 sensor 1

p0300-engine misfire detected

p0404-egr open position performance

p0405-position sensor circuit low voltage

po1139-ho25 insufficient switching bank 1 sensor 2

p1153-h025 insufficient switching bank 2 sensor 1

Now I do realize some of these codes could be from past problems, correct?

Looks like all of the codes except 300, 404 and 405 relate to oxygen sensors. If they are not working right, it will cause incorrect mixture and possibly intermittent smoke from the exhaust.

You might try cleaning the EGR valve and see if it helps the 404 and 405 error.

[KHE]

I was just wondering if anyone had anymore advice since I found out the codes.....

I'm leaning towards changing the EGR and then the oil...

Somebody mentioned that a bad egr would cause fuel to get into the oil????

First off, the coolant is brown dextron stuff, my father whom is a mechanic said it's suppose to look like a muddy color.

Well we took the car for a 75 mile drive last night, it smoked randomly on acceleration, but not at all consistent, Got it home and I jumped in the Eldorado and followed my wife, she went wot 15-80 it looked like dark white/gray smoke and just smelt like exhaust, possible running lean...

We took it for about a 35 mile spin tonight and it didn't smoke at all, had codes pulled as well....

here is what they were.

p0137-h025 circuit Low Voltage Bank 1 Sensor 2

p0147-h025 heater performance bank 1 sensor 3

p0154-h025 circuit insufficient activity bank 2 sensor 1

p0300-engine misfire detected

p0404-egr open position performance

p0405-position sensor circuit low voltage

po1139-ho25 insufficient switching bank 1 sensor 2

p1153-h025 insufficient switching bank 2 sensor 1

Now I do realize some of these codes could be from past problems, correct?

It is impossible for an EGR valve to cause fuel to get into the oil... I agree with Jim that an EGR valve cleaning is in order. There is something wrong with the oxygen sensors or wiring based on the code.

[joeb]

how long have you owned the car? if you have had it awhile, you should be aware of the timing of your codes? did they all just show up recently? or over a matter of weeks or months? dex-cool is like reddish tinted cool-ade. if you drain it into a pan, it should not be cloudy even from the disolved pellets. also your intake is "dry". no coolant or oil goes thru it. changing the intake gasket is easy but will likely only affect a miss issue, if anything. coolant leaking into the combustion chamber will give you a P0300 code as it will wet the plug and cause a misfire. but you can also have a wire/plug issue that can cause a misfire.

[fivepointohman]

First off, the coolant is brown dextron stuff, my father whom is a mechanic said it's suppose to look like a muddy color.

Well we took the car for a 75 mile drive last night, it smoked randomly on acceleration, but not at all consistent, Got it home and I jumped in the Eldorado and followed my wife, she went wot 15-80 it looked like dark white/gray smoke and just smelt like exhaust, possible running lean...

We took it for about a 35 mile spin tonight and it didn't smoke at all, had codes pulled as well....

here is what they were.

p0137-h025 circuit Low Voltage Bank 1 Sensor 2

p0147-h025 heater performance bank 1 sensor 3

p0154-h025 circuit insufficient activity bank 2 sensor 1

p0300-engine misfire detected

p0404-egr open position performance

p0405-position sensor circuit low voltage

po1139-ho25 insufficient switching bank 1 sensor 2

p1153-h025 insufficient switching bank 2 sensor 1

Now I do realize some of these codes could be from past problems, correct?

In my opinion those are to many codes to be spitting out from the PCM all at once... I would check the wiring to all those sensors. I had the same issue with codes, ened up being corrosion within the PCM wiring harness... When WOT, you will see exhaust gases black and white coming out of the pipes that is normal as the car is dumping excessive fuel to power the engine safely dont worry there... Muddy water is no good, flush out the system immediatly it should look orange. As bodybyfisher stated there is no water flowing via the intake at all, so intake gaskets are not an issue, I would put money on a head gasket starting to go bad before anything else for your smoke issue. Mind you, these car will blow a tad of oil at startup and if it is setting idle for a long period of time, mine does this and it is normal..

[lothos]

Somebody mentioned that a bad egr would cause fuel to get into the oil????

A bad Fuel Pressure Regulator (FPR) will cause fuel to get into the oil. So will a leaking fuel injector. I had a leaking fuel injector that caused a rough idle on cold startup, and a white-ish smoke out the tailpipes. The smoke smelled really heavily of fuel. My oil also smelled like gas.

[winterset]

I agree car just is running too rich.

- possibly multiple issues - (oil in coolant seems to be another issue) - I wouldn't rush to say a HG issue yet.

- EGR will make the engine run at a stalling RPM, and diesel.

- most likely (as stated, check the FPR then check the injectors for leaks).

- of those codes which were current vs. history. I would reset & see which ones come up during the day.

- check the PCV valve

- clean the intake, and make sure the oil is not overfilled now.

- oil that smells like gas. - might want to cange it right away (check the level on the dipstick), and only drive it to diagnose / or drive to a repair shop after you change the oil. It's not lubeicating the engine if it's diluted with gas. Perminant engine damage can occur. Also the rich mixture can clog up your cat.

[Ranger]

Somebody mentioned that a bad egr would cause fuel to get into the oil????

Not a chance. "Somebody" is dead wrong.