Leaking Coolant, Cracked Intake Manifold Gasket

1999 Pontiac Grand Prix (Page 1 of 2)

8.5

pretty bad
Typical Repair Cost:
$1,710
Average Mileage:
92,450 miles
Total Complaints:
22 complaints

Most Common Solutions:

  1. replacement of intake manifold (9 reports)
  2. replace intake manifold and engine (5 reports)
  3. replace intake manifold, major tune up and new oil change (4 reports)
  4. not sure (3 reports)
  5. replaced engine only to have the intakes crack again (1 reports)
1999 Pontiac Grand Prix engine problems

engine problem

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1999 Pontiac Grand Prix Owner Comments (Page 1 of 2)

problem #22

Sep 132022

Grand Prix SE 3.1L V6

  • Automatic transmission
  • 203,000 miles

A D V E R T I S E M E N T S

Car overheated several times. There appears to be coolant in the oil. It's possible that I could just replace the manifold but the mechanic wasn't sure. I'm not going to pay $500 just to find out after reading some horrific reviews on this site.

- Jeremiah S., Paxico, KS, US

problem #21

Jan 222012

Grand Prix SE 3.1L V6

  • Automatic transmission
  • 112,000 miles

I should not be the one that has to flip the bill for this . GM had known problem and has been for years . When i went to my parts place they already knew the problem . I haven't got water in my oil , i feel lucky as far as that goes . THIS SHOULD BE ON A RECALL AND FIXED BY GM !!!

- Glenn C., Akron, OH, US

problem #20

Apr 022011

Grand Prix GT 3.8L

  • Automatic transmission
  • 135,000 miles

take this to a mechanic if you are not very skilled this is a pretty tough fix for a novice

- Bradley S., Colgate, WI, US

problem #19

Jun 172011

Grand Prix GT 3.8ltr

  • Automatic transmission
  • 13,000 miles

A D V E R T I S E M E N T S

I have taken excellent care of my car , service when it needed. not sure what happened I just accelerated and the car died and now I find after pulling the a couple spark plugs that there is water in the block meaning a cracked head , manifold or whatever, my problems is that I just had my dealer replace my intake manifold gaskets about 3 months ago. would , could this be their fault or what? all i know is that the car shouldn't die from excelletrating and realy shouldn't trash the engine. its gone water in the block ite done and know way this should of happened. dealers fault certainly not mine.

- Mark J., Vallejo, CA, US

problem #18

Sep 072009

Grand Prix SE 3800

  • Automatic transmission
  • 60,000 miles

I have always loved GM, but this Pontiac has made me think twice, I had to replace the motor at 60000 miles due to a crack in the upper and lower intake,destroyed engine, then had the same problem with the new motor again luckily caught it before it damaged the motor permanently. I can't believe GM did not recall PLASTIC intake problems. Now it is leaking antifreeze somewhere again. Think it is time to get a different car>

- Kathy C., Mars Hill, NC, US

problem #17

Feb 262010

Grand Prix GTP 3.8L

  • Automatic transmission
  • 155 miles

99 Grand Prix GTP - Replaced the intake gaskets had a top end exterior coolant leak and now a week later we have a rod knocking (looks like another engine's gone) - this is the 2nd time for exact same issue - same mechanic, is the mechanic doing something wrong??? Previously was preventative maintenance at 200k same result - took out the engine

- Paul P., London, ON, Canada

problem #16

Nov 302009

Grand Prix Gtp Coupe 3800 V6

  • Automatic transmission
  • 157,000 miles

A D V E R T I S E M E N T S

like I said already thought i ranted come to find out I sent the damn thing to just one person instead of everyone... Thank God we found out before it did serious damage thanks to my excessive worrying us up all night researching symptoms and sure enough took to our mechanic of 6yrs and I was right ... and it is only going to cost the $356.00 instead of $800.00 to thousand.

- sng4ever, Adona, AR, US

problem #15

Nov 302009

Grand Prix Gtp Coupe 3800 V6

  • Automatic transmission
  • 157,000 miles

I think GMC should take take of their screw up there are enough complaints about it and why in the hell would you use plastic when and engine gets hot duh !!!!! but know we can give them bail out money but they cant hv recalls on their obvious mess up!!!!

- sng4ever, Adona, AR, US

problem #14

Apr 182009

Grand Prix SE 3.1L V6

  • Automatic transmission
  • 101,284 miles

Well we bought the car at an auction as we have with other vehicles and have always had great luck but I guess luck ran out on this one. Had it running and was running great so picked it up for $3,800... great body and interior. Got about 30 miles towards home and it was starting to overheat, so we pulled over and couldn't see fluid leaking. Topped it off but only got another ten miles before it happened again so I looked again and checked the oil and you could tell there was fluid in it. So I left it in Tofield at the shop about an hour from home and turned out it was the intake manifold gasket. So still waiting on it and being an hour away its a real pain. Wish we would have know this was a common problem.

- Ken A., Camrose, AB, Canada

problem #13

Jun 082000

Grand Prix SE 3.6L

  • Automatic transmission
  • 75,800 miles

WOW!!! I wasn't aware that every one was having this problem with the leaky valve cover issue. My problem was that the engine coolant and heat created a hole in the valve cover. The coolant then leaked into my cylinders and caused my motor to seize. this problem was on the "identified " as a problem list for the year 1998. My mechanic at the time came back from GMC certified traing and knew what my problem. I contacted GMC and they would not accept responsibility for the issue. They wanted a GMC certified mechanic to look at the motor. They went very silent when I advised them my mechanic had just returned from their training course and was certified. They still wouldn't do anything. I went to my lawyer who asked if I had 300,000 dollars for all the experts I would have to hire. Needless to say I ended up getting the new motor myself. No more GMC products for me.

- Rodney F., Morrilton, AR, US

problem #12

May 132007

(reported on)

Grand Prix GTP 3.8 V6

  • Automatic transmission
  • 87,000 miles

A D V E R T I S E M E N T S

still bushes fault that and Pontiac's are just horrible cars power is great but problems ..... well lets just say im basically paying for 2 cars at once with just one car

- David S., Columbus, OH, US

problem #11

Mar 012008

Grand Prix SE 3800

  • Automatic transmission
  • 68,800 miles

Brought in for an oil change and found out intake manifold had crack allowing coolant and oil to mix in the engine, which creates a sludge. This sludge doesn't allow the engine to lubricate itself properly so it overheats, cracks block etc.. GM is a piece of sh*t for not recognizing this problem and doing a recall!

- Brooke O., Poway, CA, US

problem #10

Mar 102008

Grand Prix 3.1L V6

  • Automatic transmission
  • 101,000 miles

The intake manifold cracked causing coolant to leak into all cylinders of the engine and even go as far as into the exhaust system. It ended up to be a very sh*tty ordeal....had to get a replacement engine for the car. It was just a pain in the ass

- Sean S., Pocatello, ID, US

problem #9

Nov 162007

Grand Prix 3800 Series V6

  • Automatic transmission
  • 96,537 miles

The FUHK'N Plastic intake manifold melted a hole from the EGR chamber to the coolant chamber,which allowed coolant into engine. Hydrolocked engine with water and oil mixture.(Solution) Had system purged, new intake manifold installed, major tune up and new oil change. $750 problem with year warranty. Takes 3 hrs to fix! Signs of same problem: while driving, continuous flashing service engine soon light, car drives like the tires are flat, excess exhaust, stinky coolant smell inside of vehicle, the car will accelerate but only to about 40-60 mph. Not to mention I only had the car 3 months and I just got paid as soon as it happened, ain't that a Bitch!!!!!

- vintagebuddy86, Detroit, MI, US

problem #8

Sep 202007

(reported on)

Grand Prix GT 3.8L

  • Automatic transmission
  • 124,633 miles

I bought my vehicle 01/13/03, 19 yrs old, first car ever, buying on my own, the car had less than 50,000 miles on it, three months later and 8,000 miles later, my engine stalls, it froze up, i had the car towed to a shop and they checked it and said the intake manifold had an eternal leak on the inside and ended up frying your motor little by little, there was no sign of any leaking, and you cant tell by the naked eye that it is going on, u have to have the equipment to test and tell. It ended up costing me $6,232.00 to replace the engine and intake, and even the radiator, when the intake had a crack in it, it leaked water into the engine oil and contaminated my cooling system. GM should of done a recall on this part, this is the only thing that is plastic on the engine, that is connected to the engine, a engine produces constant heat as it runs, up to 220 degrees at normal running temperature, heat melts plastic, i had to get a personal loan to fix this problem and i ended up going in to debt because of this. If you own a gm or anything made by the company get rid of it.

- Hubbard Jr S., Ca, 95820, US

problem #7

Sep 202007

(reported on)

Grand Prix GT 3.8L

  • Automatic transmission
  • 124,633 miles

I was having trouble with my transmission so i took it in and had it rebuilt, less than 3 weeks later it went out again, my warranty i got with the rebuilt covered it, why they were fixing that they found out that i had a blown head gasket, so i sent it to the shop where i originally had the engine replaced, they found that my intake manifold has an eternal crack in it again, this is the second time, this time i caught it before it became a bigger problem on my engine. It blew my head gaskets and my radiator, fried my tranny, ended up voiding my warranty on my engine cause of the intake, this is the second time it has done this. I am pissed off and it is causing me to stress, i am in debt still from the first time this happened. I am near losing my job, so now i am dealing with the California dept of new and used vehicle bureau and they are going to deal with gm out of court if they dont want to settle then i am going to take them to court. There should be a recall on this intake they are using. Ford had the same problem on there crown victoria and they made a recall on theres. This is not right, there are to many others having the same problem and gm is not caring, and doing nothing about it.

- Hubbard Jr S., Ca, 95820, US

problem #6

Sep 112007

(reported on)

Grand Prix LX 3.1L V6

  • Automatic transmission
  • 49,070 miles

Had to replace the intake manifold gaskets. Cost $894.00. Glad I had it done. A new engine is a lot more expensive. GM really needs to address this instead of listening to the Cost Accountants trying to save them a few dollars per car. This is a real pain. To note this problem exits on 3.1L, 3.5L, 3.8L, and 5.5 L GM engines. Not just on Pontiacs but on all GM products for example: GMC, Buick, Oldsmobile, and Cadillac. They need to address this problem because it is making customers very angry and is easily fixed by using a non-plastic gasket material. My mechanic had to replace his on his wife's Suburban. My mechanic told me on my wife's Buick LaCrosse to watch and see if anything is leaking from the gaskets and bring it in when I start seeing it. Her car only has 23,894 miles on it.

- Steve I., Manro, TX, US

problem #5

Jan 112007

(reported on)

Grand Prix GT 3.8L V6

  • Automatic transmission
  • 64,000 miles

Plastic intake manifold melted a hole from the EGR chamber to the coolant chamber, allowing coolant into engine. Hydrolocked engine. Had system purged and new intake manifold installed... ~$950... 2 weeks later engine went bad. Had used engine installed ~$1800. Lasted 2 weeks, had another used engine installed $500 (mechanic split the labor, engine covered), within 12 months, replacement intake manifold melted allowing coolant into engine, caught early but still another intake manifold. (mechanic did no charge, great guy)... engine seemed fine for the next 6-12 months when car was totaled due to failure of brakes (mechanically sound, full pads, no leaks, fluid still full). GM wouldn't do a damn thing about it, even under their "goodwill" warranty. See petition of intake problems on ~98-02 3.8L V6 engines (Venture, etc) at http://www.petitiononline.com/GMcnsmrs/petition. html (13555 signatures so far), yet it isn't a design flaw!? Wish I could file small claims but don't know business & address to file against. Puts a BAD taste in my mouth!... and this was my dream car, saved 7 years for and paid cash!... never again!

- Dan K., Syracuse, NY, US

problem #4

Feb 152007

(reported on)

Grand Prix GT 3.8

  • Automatic transmission
  • 72,000 miles

heard this is a problem with this engine because the plastic melts, think GM would rectify and help out

- katiesp, Spencerport, NY, US

problem #3

Feb 122007

(reported on)

Grand Prix GT 3.8

  • Automatic transmission
  • 48,000 miles

GM has a history of this same issue and yet does nothing...

- dsolberg, Omaha, NE, US

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