GM 3.4L V6?

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Mu uncle just adopted a Monte Carlo (2001) with this engine. I have ZERO experiance with it, is it any good? I know it has a similar engine to the Grand AM. Thing is, it has 175K on her so I'm not sure how they hold up. Opinions welcome! TIA
 
It's a bored out 3.1 60* V6.
They were prone to intake-manifold gasket failures.
If the gasket is replaced with a Fel-Pro Problem Solver they are capable of high mileage. (I have seen several on here with over 300K and one owner claimed 800K...although he claimed they need an I-M gasket every 200K regardless ....)
They are also economical if not powerful. I have gotten well over 30mpg highway with my 3.1 on long trips.
 
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Originally Posted By: pbm
It's a stroked (or maybe bored out) 3.1 60* V6.
They were prone to intake-manifold gasket failures.
If the gasket is replaced with a Fel-Pro Problem Solver they are capable of high mileage. (I have seen several on here with over 300K and one owner claimed 800K...although he claimed they need an I-M gasket every 200K regardless ....)
They are also economical if not powerful. I have gotten well over 30mpg highway with my 3.1 on long trips.



This....
 
I liked mine in my silhouette. It was noisy when cold but torquey and got 26 MPG going extra legal speeds with the AC on and a van full of stuff. It matches the 4 speed auto they stick beside it perfectly.
 
The GM 3.4 is a very study engine except for one thing: the lower intake manifold gaskets. Commonly referred to as the LIM. At that mileage, I'm sure they've been replaced at least once. If the repair was done with Fel-Pro gaskets, you'll never have to do it again. If you keep coolant out of the oil, these engines have been able to top 250 K pretty easily. They are also known for some clatter/tick upon cold start. This generally goes away within 30 seconds. Most just ignore it, it is a trait of this engine and fades with warmup. I use HDEO 15W40 in the summer and the recommended 5W-30 in the winter.
 
...I should have added to tell your uncle keep his eyes on the coolant tank level as loss of coolant is the main sign of I-M leakage. It might be wise to throw a bottle of Barsleaks in it until you ascertain whether it's leaking.
It's not a matter of 'if' it will leak but rather of 'when'....

Mechanics are familiar with the job and many will do it for less than $600...(maybe even less in Iowa)..
 
If you have no records that the LIM gasket has already been replaced then I would do an oil analysis to see how much coolant is in the oil.

You can not see the coolant in the oil so you are wasting your time doing a visual on the oil. The lab called me back with the bad news.

Some of these engines (including mine) also have had problems with head gaskets but that may be related to the LIM and Dexcool.

I changed the coolant to G-05 after doing the LIM twice and the heads.
 
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the factory LIM gasket is plastic which the dexcool's 2-EHA eats up over time. So felpro's updated gasket solves the issue.
these motors have a lot of oomph as well as reliability (aside from the intake gasket)
They're relatively easy to work on too.
 
qsoil.jpg


My wife's grand am has had a steady diet of 1985 10-40 oil lately without complaint. Gotta be a tough engine!
 
Originally Posted By: ridgerunner
qsoil.jpg


My wife's grand am has had a steady diet of 1985 10-40 oil lately without complaint. Gotta be a tough engine!

lol
 
They're one tough engine. There are two 3400's in older GM minivans that are still running okay despite lifetimes of indifferent at best maintenance. They sound like death warmed over when first started, but they go and get mid-20's fuel economy.

In a lighter Monte Carlo, they should be capable of 30+ mpg highway when driven sensibly.
 
Originally Posted By: artificialist
I have replaced head gaskets often on this engine.

I don't like the 2.8/3.1/3.4 engines.


I hear this often - and wonder whether there is a connection between head gasket failure and a previous LIM gasket failure resulting in an overheating condition and subsequently compromised head gasket...
 
Yet it's actually a relatively small amount of the engines produced that require new LIM and/or head gaskets.

Fel Pro Problem Solver (hint).
 
Originally Posted By: pbm
It's a bored out 3.1 60* V6.
They were prone to intake-manifold gasket failures.
If the gasket is replaced with a Fel-Pro Problem Solver they are capable of high mileage. (I have seen several on here with over 300K and one owner claimed 800K...although he claimed they need an I-M gasket every 200K regardless ....)
They are also economical if not powerful. I have gotten well over 30mpg highway with my 3.1 on long trips.


My sister has the 3.1 v6 in her '95 Cutlass Supreme, and we had to replace the LIM gasket at around 165,000 miles. Water pump went at around 170,000 miles, and it was one of the easiest water pumps to replace that I've ever seen. The setup is the same on the 3.4L. The engine currently has over 180,000 miles, and burns virtually no oil over 5-6k mile OCI's.
 
The wifes impala gets over 30mpg. We were lucky to get the 2005 which is supposed to have a better gasket that is less prone to earlier issues. The engine has been awsome so far. Its the trans that sucks!!!
 
Originally Posted By: MuzzleFlash40
The wifes impala gets over 30mpg. We were lucky to get the 2005 which is supposed to have a better gasket that is less prone to earlier issues. The engine has been awsome so far. Its the trans that sucks!!!


X2 on the trans. I replaced my wifes at about 60,000 miles.
 
Originally Posted By: ridgerunner
Originally Posted By: MuzzleFlash40
The wifes impala gets over 30mpg. We were lucky to get the 2005 which is supposed to have a better gasket that is less prone to earlier issues. The engine has been awsome so far. Its the trans that sucks!!!


X2 on the trans. I replaced my wifes at about 60,000 miles.


I'll actually have to disagree with your statement about the transmission. The 4-speed AT in my sister's Cutlass Supreme has about 185,000 miles on it, and still shifts and works great. I had the exact same transmission in my 2.4L grand am, with 174,000 miles, and that transmission shifted perfectly too. I had thought that the same 4-speed AT was also used for the 3.4L, but I could be wrong.
 
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Originally Posted By: Klutch9
Originally Posted By: ridgerunner
Originally Posted By: MuzzleFlash40
The wifes impala gets over 30mpg. We were lucky to get the 2005 which is supposed to have a better gasket that is less prone to earlier issues. The engine has been awsome so far. Its the trans that sucks!!!


X2 on the trans. I replaced my wifes at about 60,000 miles.


I'll actually have to disagree with your statement about the transmission. The 4-speed AT in my sister's Cutlass Supreme has about 185,000 miles on it, and still shifts and works great. I had the exact same transmission in my 2.4L grand am, with 174,000 miles, and that transmission shifted perfectly too. I had thought that the same 4-speed AT was also used for the 3.4L, but I could be wrong.


I know that it is a common problem for the 200-2005 impalas. Look at the autobeef.com web site. We've put 3 transmissions in the thing. When she gets back to work it is going bye bye, lol
 
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