98 Pontiac Grand Prix help!

[TR Custom Parts]

Figure someone here has to no about these cars. There is probably more knowledge here than on the Pontiac GP boards. We don't know how lucky we are to have this board, believe me.

Anyway, got a 98 Grand Prix GT. Was my mother in laws car and when she passed away last year we kept it as a backup vehicle. Took it out tonite and it started hesistating a bit but figured it might be old gas or something. Got progressively worse to the point that it was misfiring and starting smoking. BLACK. Limped it on home and scanned it and got a P0301 which is a cylinder #1 misfire, think there may be more codes but now it won't even start.

Cranks over but tons of smoke coming out the exhaust. Nosy neighbor came over so I just shut the hood and called it a nite. Since it is a backup car it wasn't a top priority but do want to get her running again.

Think this might be the symptoms of a bad MAF?? Going to see if it will start up in the morning and try unplugging the MAF to see what happens. I'll tell you, these W body cars are real loads.

 

[chris mccord]

Well a MAF will usually set a code but not always. Try unplugging the MAF, if it runs then that's your problem.

 

[gsgns4me]

Is it a 3.8L or a 3.4L?

 

[chris mccord]

Gt=3.8

 

[gsgns4me]

Gt=3.8

Thanks! I couldn't remember if they had quit using that dual overhead cam piece of.....uh, er, boat anchor by then.:tongue:

 

[chopped39]

Unplug mass air and see if it starts .Fuel pressure regulator? Pull vacuum line and see if there is fuel there. sounds like its flooded. try clear flood and see if it helps.If it starts in clear flood you have a leaking regulator or leaking injector. You said there may be other codes.rescan it and post codes .

 

[my1stgn]

the 98's had a problem where the coolant would leak into the intake and cause misfires and the engine to hydro-lock. The problem being is that the plastic intake manifol had a metal tube inserted in it where the egr went back into the intake. wel when the tube got hot is melted the manifold and the coolant passage for the throttle body ran right next to the metal tube for the egr. Thus you have coolant in the intake. The newier design now has aluminum tube for the egr and a gap between the egr tube and the plastic manifold. check your coolant, if its low .......:frown:

 

[wile87]

black smoke usually indicates high carbon build up. anti freeze is light gray to white with sort of a sweet smell to it. i doubt that is coolant and you say it spins so it isn't locked up. could be bad coil pack. i think mod and coil are one piece on that motor

 

[chris mccord]

black smoke usually indicates high carbon build up. anti freeze is light gray to white with sort of a sweet smell to it. i doubt that is coolant and you say it spins so it isn't locked up. could be bad coil pack. i think mod and coil are one piece on that motor

I agree coolant would be white. These do have 3 separate coil packs.

 

[garyk1970]

the 98's had a problem where the coolant would leak into the intake and cause misfires and the engine to hydro-lock. The problem being is that the plastic intake manifol had a metal tube inserted in it where the egr went back into the intake. wel when the tube got hot is melted the manifold and the coolant passage for the throttle body ran right next to the metal tube for the egr. Thus you have coolant in the intake. The newier design now has aluminum tube for the egr and a gap between the egr tube and the plastic manifold. check your coolant, if its low .......:frown:

this true,ive seen it myself.theres no other evidence other than no run condition. ive seen fpr full of gas (pull vacumn line and look) and ive seen injectors stick open. maf as said before is a good lead too.other usuall stuff; crank sensor, low voltage/bad grounds corrosion,etc

 

[TR Custom Parts]

the 98's had a problem where the coolant would leak into the intake and cause misfires and the engine to hydro-lock. The problem being is that the plastic intake manifol had a metal tube inserted in it where the egr went back into the intake. wel when the tube got hot is melted the manifold and the coolant passage for the throttle body ran right next to the metal tube for the egr. Thus you have coolant in the intake. The newier design now has aluminum tube for the egr and a gap between the egr tube and the plastic manifold. check your coolant, if its low .......:frown:

THINK we may have a winner. To tell you the truth, I was so pissed at this damn car that maybe the smoke was more grayish white than black, was dark out.

Anywho, pulled the MAF connector and went to crank it over and the motor IS locked!

Should have done this first! Checked coolant overflow tank, empty, checked radiator, can't see any coolant, checked oil, OVERfull!

Pulled all the plugs, real fun getting the firewall ones out, curse GM! All plugs were wet and smelled like fuel but not strong. Cranked over the motor and pumped all sorts of stuff out, definetly coolant. I am sure the extra fuel was in there from cranking it and not starting.

Guess I should do a compression test first to see if it blew a headgasket? Hoping it IS the intake so I don't have to pull a head(s).

Will get the oil drained out before the bearings get contaminated, car only had about 10-15 minutes of drive time on it.

 

[chris mccord]

THINK we may have a winner. To tell you the truth, I was so pissed at this damn car that maybe the smoke was more grayish white than black, was dark out.

Anywho, pulled the MAF connector and went to crank it over and the motor IS locked!

Should have done this first! Checked coolant overflow tank, empty, checked radiator, can't see any coolant, checked oil, OVERfull!

Pulled all the plugs, real fun getting the firewall ones out, curse GM! All plugs were wet and smelled like fuel but not strong. Cranked over the motor and pumped all sorts of stuff out, definetly coolant. I am sure the extra fuel was in there from cranking it and not starting.

Guess I should do a compression test first to see if it blew a headgasket? Hoping it IS the intake so I don't have to pull a head(s).

Will get the oil drained out before the bearings get contaminated, car only had about 10-15 minutes of drive time on it.

If you pull the intake you can see where the EGR burned through.

 

[TR Custom Parts]

Did a compression test and the numbers are all over the place.

1- 165 lbs
3 - 210 lbs
5 - 165 lbs

2 - 150 lbs
4 - 135 lbs
6 - 210 lbs

Now this is on a car with 120K on it and not sure what having all that coolant in the cylinders is going to do for the compression numbers???

One more thing, this was done on a cold motor obviously since it won't run so that might skew the results for the test.

So if intake is the problem can I get away with just replacing the plastic part or do I have to do the lower as well???

Going to grab some lunch and let my arms begin to heal. Freaking firewall is tight to the heads. I hate FWD cars.

 

[chris mccord]

The lower intake manifold gaskets have issues as well. I'd replace the upper intake and replace the lower gaskets. These motors just start to break in at 120k. As long as the coolant hasn't been in the oil too long.

 

[gunslinger]

Don't worry about the compression #s yet. The rings probably just got washed by all the coolant. I've done a ton of these, and have only had one engine not live after upper intake replacement. While the upper is off, you should do the lowers too.

Do yourself a favor and get a Dorman intake from Napa. The EGR burn through prblem gets solved with these...and don't forget the PCV valve...they sound funny when you forget to put them in. :smile:

Once the upper plenum is replaced, that thing is going to smoke for a while...lots of coolant to burn off the cat.

 

[chris mccord]

O2 sensor could die as well from the coolant.

 

[TR Custom Parts]

Good point on the 02 sensor. Once I get this POS back in shape I think I am going to blow it out the door. ABS/Trac lights have been on forever and I think the climate control is crapping out as it blows hot air only, no AC even though the compressor is engaged and the charge is good. It does look nice though and is the right color, black.

 

[chopped39]

dont forget to replace plastic elbow from tensioner to lower intake.Get it from the dealer.Dont get aftermarket one it will split down the road.

 

[my1stgn]

Good point on the 02 sensor. Once I get this POS back in shape I think I am going to blow it out the door. ABS/Trac lights have been on forever and I think the climate control is crapping out as it blows hot air only, no AC even though the compressor is engaged and the charge is good. It does look nice though and is the right color, black.

Check your fuse for the abs. It also controls the ac. People pull this fuse to disable the traction control because that tcs off button doesnt do much. I could bet money that the fuse is burnt or missing. If this is true, then Im 2 for 2. Autozone also sells Dorman products and they have the moded aluminum piece for the egr. Compression for the cylinders maybe higher because they still might have coolant in them, dont know. What till you get the engine running then do another compression check. But if anything check the fuse for the abs and that should fix your ac problem (you could thank me later:biggrin: ) and let me know if you have any other questions.:wink:

 

[TR Custom Parts]

More GP questions-fuel injectors

While I have everything torn down was thinking about doing the injectors at the same time. Wonder if these are too good to be true?? Will the 2000 up injectors work on the 98? Sure looks like the same exact fuel rail setup.

eBay Motors: Fuel Injector 3.8L 3800 Buick On Fuel Rail New (item 130240719869 end time Oct-19-08 12:20:49 PDT)