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98 grand prix gt po108 and po107 white smoke

R

robjr80

New member
I have a 98 grand prix GT and my problem started with a cracked radiator. the car got hot one day and as soon as it hit the red I stopped the car to let it cool. I changed the radiator and I starting loosing coolant at almost a gallon a day a couple days later and 2 days after that I seen water in the oil so I parked it. thought I had blown the head gasket but when we tested the compression I was getting about 120 pounds on all cylinders. so next I looked around online and seen there are a lot of issues with the upper intakes and intake gaskets on this engine. so I bought a new upper intake and gaskets and lower intake gaskets. when we took it apart sure enough the lower intake gaskets were blown out in 3 places. we put it all back together changed the oil, plugs, wires, went ahead and changed the valve cover gaskets too. when I first started it the engine light came on but the next day it went off. the day after that the light came on again and it started idling a little rough and it sputters a little bit when you take off and I noticed a little white smoke coming out the tail pipes. I'm getting codes po107 and po108. it didn't act up like this before we took it apart it just was loosing water. anyone have any suggestions? I've already spent more money than I could afford and getting really frustrated.
 


those are both map sensor codes. make sure its plugged in and its vac line is on. check for leaks in the vac lines you just touched. most of the time they dont make it through a lim job and need replacing, or at least a repair done to one or two.
 
I checked those yesterday. the map sensor just snaps in the side of the upper intake. I pulled it out to make sure the o rings were on securely and it fits tight to the intake. and I'm only seeing 2 vac lines. One goes to the throttle body and the other connects to the back of the intake. They look fine and I'm not hearing any air or anything. I've tried everything I can think of except check the voltage on the censor wires. I'll have to get ahold of a meter.
 
no not yet. I read on another web site to check vac lines and check the voltage and ground going to the sensor first. I was hoping someone on here had had the same issue and it turned out to be something simple. I've spent over 400 dollars on it the past 2 weeks. a new map costs around 70 dollars at the parts stores around here and I just don't have it right now.
 


White smoke??? You're burning coolant. Get a Block Tester from your auto parts store's tool loaner and do a quick check to make sure the head gaskets aren't blown.

If the head gaskets are OK, time to replace those intake manifold gaskets along with the parts that are throwing the codes.
 
I just replaced all the intake gaskets upper and lower and a new upper intake. we did a compression test on the plug holes and was getting around 120 psi on all cylinders so we assumed the head gaskets were good. the white smoke is so rich smelling it will burn your eyes and nose.
 
I guess I need to go get a block tester and check that. me and a friend of mine went over this thing until it got dark last night. I'm getting the right voltage to the map sensor and have no vac leaks. I did notice that the pcv valve has a little of that milky looking oil around it even though the oil in the motor looks brand new. the smoke has gotten worse and the radiator cap it dripping. the car had also lost almost a gallon of coolant this week I find it hard to believe that drip could loose that much coolant. it's looking like I might have a blown head gasket even though I'm getting good compression but I've read everywhere the head gasket on these motors are very hard to blow. starting yesterday the car is also not wanting to fire right up like it normally does. It's starting to turn over longer before it fires. like I said in the other post the smoke is really rich smelling like the engine is getting way too much gas. I'm going to have to park it until I get this figured out because I sure don't want any more damage done. this is the 3800 series 2 motor.
 
well I put a new map sensor on it and still no luck. engine light is still on with the same codes p0107 po108. it still smoking white smoke pretty bad too but there none in the oil and still loosing water.also I left it sitting for 4 days and when I opened to radiator cap it had so much pressure in it you would have thought it was hot. it even blew coolant out of the over flow tank? it's never done that before when the engine is cold.has anyone ever had any luck with that head gasket sealant?
 


I've printed off everything you guys have told and showed me and I'm going to take it apart again this weekend. wish me luck and thanks a lot for your help. this is the only site where guys have tried to offer me any help. glad I found your site. yes I only went over the lim bolts once. the upper intake is new but I did not change the stove pipe because I didn't know what is was. the instructions didn't say anything about changing it but I'm going to go over the whole thing again.
 
If the UIM is new, then it shouldn't be the issue.

Have you checked that the pcv is correct? There should be one o-ring on the bottom of it and then the cap has an o-ring. Also.. if you could post up pictures beforehand that may give us some info. I am thinking something small or silly is causing this issue.
 
If you only went over the LIM bolts once that's your problem. Once you torque down one side the other becomes loose. I generally go over all the LIM bolts 3 times before putting the rest of it together. I bet if you pull off the upper and half the bolts will be pretty loose.
 


I don't have a digital camera so I can't post photos but I have checked it several times. I've pulled it out several times to check it.both the o rings you mentioned are on it but the one that goes around the pcv is a little loose. it doesn't fit tight around the pcv. when I snap it back on the intake everything feels nice and snug. the housing is not loose or anything. also if this helps after I completed changing the all the gaskets and the uim and got it all back together the 2nd or 3rd time I tried to start it the car just would spin over and not fire. all I did was pull the map housing out and check the o rings and when I would put it back in it would fire right up. it has done this twice and that's all I would have to do to get it to start but that was in the first week after putting it back together. it hasn't done it again just keeps throwing up those codes and running rough with the white smoke. I'm loosing water still and too much pressure is building up in the radiator. I'm going to have to take it apart anyway to check all the torque's again like buck mentioned and change that stove pipe and double check everything.
 
I agree with the suggestion to retorque the lim bolts. There is no way they are tight if you just went over them once. The first time you tighten it down, if you were to go back to the first bolt you could probably loosen it with your fingers. You need to crisscross torque it in 3 passes up to the final spec. That's most likely the cause of your problems.
 
well I've went over the whole thing again and there is no water in the intake but still loosing water and building up too much pressure in the radiator. even thought I'm showing good compression on all cylinders I got to have a blown head gasket somewhere on one of the heads. so it looks like I'm tearing into it again. :(
 
well it was the head gasket blown. I put some carbon fiber gasket sealer in it and it stopped smoking after 5 minutes of running it and all the other issues have went away. it's been running fine for 2 weeks now.
 
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