Howdy ya'll. My girls beaten Taurus that I've mentioned on here before finally breathed its last. It cracked the back head. Word on the street is that it would have cracked a cylinder in less than a year if fixed, so I bought her a super clean '99 Malibu with 73kmi on the clock. It's a strong running car, but I've read many a post about the intake manifold leak. What should I look out for with that issue, and what else is an issue with this car? Thanks guys.
New (used) Malibu with the dreaded 3100
- Thread starter carrera79
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Try some "Barrs Leak".
Good Luck with your new-used car.
Good Luck with your new-used car.
How much trouble is it to replace the intake manifold gasket on that engine?
Why do they run coolant through the intake manifold, anyway? (I'm guessing, perhaps incorrectly, that there are coolant passages cast into the intake manifold and the gasket leaks causing coolant to leak into the cylinders)
I replaced the intake manifold gaskets and fuel injector O-rings on a 1995 Ford Contour V6 2.5L and it wasn't terribly difficult.
But no coolant goes through the intake manifold on that car. There is no way a failure of the intake manifold gasket could cause anything but extra air to leak into the cylinders.
Why do they run coolant through the intake manifold, anyway? (I'm guessing, perhaps incorrectly, that there are coolant passages cast into the intake manifold and the gasket leaks causing coolant to leak into the cylinders)
I replaced the intake manifold gaskets and fuel injector O-rings on a 1995 Ford Contour V6 2.5L and it wasn't terribly difficult.
But no coolant goes through the intake manifold on that car. There is no way a failure of the intake manifold gasket could cause anything but extra air to leak into the cylinders.
They have some info on the updated intake gasket here:
http://www.chevytalk.org/threads/sh...95792&page=0&view=collapsed&sb=5&o=93&fpart=1
My understanding is that your car is getting to the amount of miles where the original gasket may fail. Might be worth changing it, before the original one fails, or monitor the coolant and oil closely.
http://www.chevytalk.org/threads/sh...95792&page=0&view=collapsed&sb=5&o=93&fpart=1
My understanding is that your car is getting to the amount of miles where the original gasket may fail. Might be worth changing it, before the original one fails, or monitor the coolant and oil closely.
Great.
Brian,
I agree with you, but it seems that the intake manifold gets coolant to keep its expansion rate similar to that of the engine. My SAAB doesn't do that. It's dumb, but it's the case. I'm going to do it one of these days. I guess that I'll just look for signs for now. It shouldn't be too much of a bear, but it's still a pain in the rear.
Brian,
I agree with you, but it seems that the intake manifold gets coolant to keep its expansion rate similar to that of the engine. My SAAB doesn't do that. It's dumb, but it's the case. I'm going to do it one of these days. I guess that I'll just look for signs for now. It shouldn't be too much of a bear, but it's still a pain in the rear.
I have a 3.1L also. Why would you change it before it breaks? Did they actually improve the new part? I doubt it. They've been using this engine and the 3.4L for 20+ years and have yet to fix it. Thanks GM for all the hard work
They couldnt just drop a 3800 in all those cars and charged $500 more.
I rembered reading about this problem. Hope you don't have the same demise this Malibu engine had:
http://cartalk.com/board/showflat.p...d=allposts&Main=231958&Search=true#Post231964
http://cartalk.com/board/showflat.p...d=allposts&Main=231958&Search=true#Post231964
Just so your not hearing all doom and gloom. My sister has a 2000 Malibu and no problems so far. The engine runs well and doesn't use any antifreeze. I would do a little more research before tearing into the engine. An oil analysis can tell you if you are leaking antifreeze into the oil. They did fix the intake gasket problem at some point and your 3100 may have gotten fixed already.
-T
-T
It's a full day (or weekend) job to replace the intake on the 3100. The intake leak is very common on the engines built before 2001 I think, due to combination of the design of the first design OEM gasket and the tendency of the somewhat small diameter bolts to loosen. Check the front and rear of the engine for telltale dark streaks coming from the intake.
Unlike most other V6/V8's the lower intake gasket on the 3.1 is partially behind some of the pushrods - the rockers and pushrods have to be removed to replace the gasket! However, at least they bolt in and out - no running adjustment is needed to set lash. Still a hassle - be sure to keep them all in order.
The upper plenum, intake rail/injectors, valve covers and all kinds of other stuff has to be removed. The power steering pump can be left connected and moved out of the way. You will need gaskets for the upper and lower intake, o-rings to re-install the injectors, valve cover gaskets, and an o-ring to re-connect the fuel rail to the line fitting.
The factory setup on the fuel rail connection is sort of a press-fit. Takes some grunt to break it loose after the nut is loosened. Just pull it loose but be SURE to use an o-ring when you re-connect it. Check to ensure there are no leaks before installing the upper plenum, otherwise you'll have to take it off again to repair leaks. Just turn the ignition on - the fuel pump will come on briefly to pressurize the system.
Use Fel-Pro or Victor Reinz gaskets - they are very dependable in the long run. Of course be sure to clean all (aluminum) surfaces very well - if there is corrosion it must be lightly sanded/cleaned as well.
It's a lot of work, but better to spend less than $50 in parts than the $500-$800 for dealer charge. Get a Haynes manual and it will help walk you through most of the process, plus gives you the torque values.
Our 3100 is in a 99 Olds Cutlass - clone of the Malibu. It also has the common tick noise that some of these engines have at cold start - not bad but annoying. Other than that, this engine does not use any oil, runs well, and has been very dependable. But - I take issue that GM did not foresee or care about the intake leaks/noise, both of which are well documented and correctable thru factory TSB's, which to me means they were aware of it.
Anyway, it's a fairly big job to replace that lower intake gasket, but worth the time to save big $$ shop costs. Plus if you're handy you know that it's been done right!
Unlike most other V6/V8's the lower intake gasket on the 3.1 is partially behind some of the pushrods - the rockers and pushrods have to be removed to replace the gasket! However, at least they bolt in and out - no running adjustment is needed to set lash. Still a hassle - be sure to keep them all in order.
The upper plenum, intake rail/injectors, valve covers and all kinds of other stuff has to be removed. The power steering pump can be left connected and moved out of the way. You will need gaskets for the upper and lower intake, o-rings to re-install the injectors, valve cover gaskets, and an o-ring to re-connect the fuel rail to the line fitting.
The factory setup on the fuel rail connection is sort of a press-fit. Takes some grunt to break it loose after the nut is loosened. Just pull it loose but be SURE to use an o-ring when you re-connect it. Check to ensure there are no leaks before installing the upper plenum, otherwise you'll have to take it off again to repair leaks. Just turn the ignition on - the fuel pump will come on briefly to pressurize the system.
Use Fel-Pro or Victor Reinz gaskets - they are very dependable in the long run. Of course be sure to clean all (aluminum) surfaces very well - if there is corrosion it must be lightly sanded/cleaned as well.
It's a lot of work, but better to spend less than $50 in parts than the $500-$800 for dealer charge. Get a Haynes manual and it will help walk you through most of the process, plus gives you the torque values.
Our 3100 is in a 99 Olds Cutlass - clone of the Malibu. It also has the common tick noise that some of these engines have at cold start - not bad but annoying. Other than that, this engine does not use any oil, runs well, and has been very dependable. But - I take issue that GM did not foresee or care about the intake leaks/noise, both of which are well documented and correctable thru factory TSB's, which to me means they were aware of it.
Anyway, it's a fairly big job to replace that lower intake gasket, but worth the time to save big $$ shop costs. Plus if you're handy you know that it's been done right!
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