1995 Pontiac Grand Am Head Gasket & timing chains

HOBO65689

MEMBER
1995 PONTIAC GRAND AM
4 CYL
FWD
MANUAL
179,000 MILES

It all started after 137000 miles it blew the timing chain & bent all the valves. I replaced all parts that were bad but it only lasted 4 months (about 3000 miles) & went again.I thought it was a faulty tensioner( replaced every time) also replaced the head 3 times. My auto parts store is saying Im using the wrong head gasket & overheating the timing chain causing it to streach & fail. But temp gauge shows normal temp (Early veres late 95) when I buy a gasket set 2.3 the cam housing tops have a green gasket (intake)but the gasket set only has red & they don't fit so I have to order 2.4 cover gaskets (intake only). I have a head with the 456 stamp. My question is if there is a early or late in the 95 model would the late be a 2.4 The car is a 95 SE coupe vin "D" Have you got any Ideas. This will be my last time with this repair. Great car but this problem has me down.I see in 96 they changed to 2.4 but mine has the 2.3 exhaust bolt pattern. Should all water ports on block & head be open tru head gasket or are they made with restrictions? Thanks for your time. Duane

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RACEFAN966

MECHANIC
5,029 POSTS

You did check the other pulleys for any missalignment. Did you check the cogs on the belt to make sure you didn't get a belt with square cogs instead of round cogs or visa versa. How is the cam and crank gear any wear or sharp edges? These all the things I would check. Thanks

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Tuesday, December 30th, 2008 AT 12:05 AM

HOBO65689

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9 POSTS

This is a 2.3 DOHC it has a chain not a belt & I have replaced the gears ( all 3 ) each time the chain stretched out. I have a rebuilt head to do the repair again but I'm looking for a cause to this problem before I do. Remember this has happened 4 times in about a year. It runs great for about 3 or 4 months then it slips time & bends the valves. My local part store says head gasket is wrong( heat causing the chain to stretch) because it is a late 95 model ( I don't really buy the early & late Idea) but when they order me a late gasket it says 96 2.4. I thought it might be in the cam housings but I see no wear or trouble there. Can I use 2.4 cam housings & cams? My thinking is the chain only turns the cams so the cams have to be binding causing the chain to stretch. But I see nothing to prove this thought. Thats my problem Nothing stands out as the cause. What do you mean square clogs or round clogs. When the motor is running it holds a normal temp. I just need to figure this out before I do it again. Thanks for your time. Duane

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Tuesday, December 30th, 2008 AT 6:43 AM

RACEFAN966

MECHANIC
5,029 POSTS

Thats right my bad so many cars are belt driven I didn't even think about the Quad being chain driven. Ok has the head been shaved and if so how much? If the head has been shaved to far then you need a head shim this will bring the head back to the factory height and everything will run as it should. Now on the timing chain are you buying the chain and gear seperately or in a kit form. I recomend a kit so all it a matched set. If the cams are binding then the head has been gaulded from lack of oil which would show by being discolored usually a bluish color. The different cogs only relate to timing belts not chains so this is not a problem here.
Here is something interesting. Just so you know I am ASE Certified as a mechanic and as a Parts Pro so this is stuff I think about as I try to help customers at work when stuff goes weird like this. What is the production date of you car and what is the 8th digit of the vin? If you are on a production split where some parts on your car are from 94 model year (this is more common then you think) then there is a second timing set available. So what I am saying is if you are buying this the timing in seperate pieces then you may be getting the wrong chain or gears. If you give the part numbers I can check it at work too with all the other needed info and get you a part number so go with. Get back to me and we will go from there.

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Tuesday, December 30th, 2008 AT 10:01 AM

HOBO65689

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Hi: The production date is 11/94 & the the 8th digit in the vin is a "D". So that take care of the early verus late deal. Let me give you a little history. The first time it broke I hired a ASE mechanic & it ran great for 3 1/2 months then one day my daughter shut it off at wal-mart came back out & tried to start it & it bent all the valves. Now I'm thinking if you want it done right do it yourself so I did the next repair. Buying the chain & gears in a kit. The head was resurfaced but I don't know by how much. It also went 3 1/2 to 4 months( less than 2500 miles) it did the same thing again. Every time I take it apart the timing chain is stretched out & the tensioner is broke. ( The little clip that locks it out) You said there was another timing set for a 94 model? When timing this engine I use the 8mm bolts as directed & like I said it runs just perfect. One would think I would have no problem seeing what is causing this to happen over & over but I just don't see it. I'm open to any Ideas before I put it back together one more time. Thanks again for your time Duane

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Tuesday, December 30th, 2008 AT 1:24 PM

DOCFIXIT

MECHANIC
18,828 POSTS

Hi hobo
How about this insufficent oil to chain. Is it oily when you tear down? Oil to tensioner could be O.K. But there is passage way that gravity feeds oil to crank gear where it is slung around. If galley way cloged no oil chains gets hot stretches and boom.