97 STS smokes on accel

NYSpeed Automotive
1

I am looking into buying a 97 STS with 77k, It’s a pretty good deal, but there is a problem, I am trying to figure out exactly what it might be so I know what to offer or if I want it at all.

Everything is fine till the car is up to temp (about 10mins) then it starts smoking pretty bad while accelerating. While just cruising it’s fine, It also doesn’t over heat. Oil is low and coolant looks brown and nasty…

A gm tech told me it’s possibly the intake gasket, but I know head gaskets are possible too on these vehicles, I’ve also been told that it might just be a sensor (hard to believe)

Any suggestions would be nice or tips from personally experience… Any other ways to check to see exactly what the problem is?

Thanks
-Jim

2

After the motor heats up? Nasty coolant - and low oil? Sounds like your tech is right, a blown gasket - or - a cracked cylinder head. White smoke, right? Engine heats up, expansion, then issue.

3

I’d vote ehad gasket or cracked head, but these are generalzations as I don’t have a lot of hands-on on these motors.

4

Most common thing on these cars is crappy piston rings and piston to wall clearance. Done a few on warranty.
You situation seems to be a headgasket/cracked head issue. The first telltale sign is the “as soon as it heats up”. Thats when your coolant is flowing and this is when you’re smoking. Pressure test the cooling system and see if there is any pressure loss/ or rapid building of pressure. If it rapidly builds pressure when cold you have an exhaust leak into the cooling system. If you have a pressure loss you are leaking out through an HG or a cracked something or other.

5

^ what he said, junk it!

sorry but tis true…

no but really, does it have a CEL on???

6

do you mean a car phone? Yes

7

haha

8

tell the current owner to have the mad scientist tear down the block and replace the piston rings he fried

F&F aside, i’d look for a crack somewhere

9

Northstars have weak rings.

Deff sounds like a crack or one of the 3 gaskets mentioned, none of which are cheap to fix on a fucking northstar

10

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?

haha PS: just watched that Saturday, OWNAGE

11

Oh…That…

yea, all that is is valve float, all northstars do it when you floor it.