can I put a 3100 into a GT body?
- Thread starter willalmo
- Start date
The 3.8 is not a bad engine but nor is the 3.1. As stated previously, if you are not modding the engine, very little difference. The OP said nothing about modding the engine. The LIM problem is associated with both engines, not debatable. The head gasket issue is definitely out there as well with the 3.8-do a search-its all over the internet. Saying the 3.8 does not have any head gasket issues along with the 3.1 is downright misleading...
I am just curious if have ANY of you have driven GM vehicles with the 3.8 for 150,000 miles AND a 3.1 for 170,000 miles?
Arguing about 20 HP difference on any engine on any car is ridiculous…..
I am just curious if have ANY of you have driven GM vehicles with the 3.8 for 150,000 miles AND a 3.1 for 170,000 miles?
Arguing about 20 HP difference on any engine on any car is ridiculous…..
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Sven the Sexman
New member
Just because someone SAYS they blew a HG on a 3800 99% of the time this is not the case. Most of the time it's LIM gasket failure. I've been dealing with the 3800 for years as have many others here...HG issues are nearly nonexistent compared to the 3100/3400 fiasco.
You are 100% correct but you are totally wasting your time with the 3.8 crowd that will call you names, tell you how dumb your are, and frankly despise anyone who does not bow to the "mighty" 3.8. Frankly, they should stay in the 3.8 section of the forum if they have nothing constructive to add….
Sven the Sexman
New member
I have not once called anyone names. I know more about the 3100/3400 engine than most thanks to fixing them for years. If you want to talk reliability then the 3100/3400 is simply not in the same league as the 3800 engine. There's a reason the 3800 was on the list for one of the best engines ever made and the 3100/3400 was not...it has to do with design. Calling me a 3800 leghumper is by far not true...it's a great engine and does what it needs to do. I moved away from the engine and the platform for other reasons.
BillBoost37
New member
Jumping in here.. finding the conversation odd as I have done a lot of work in these as well.
Plastic intake gaskets were clearly a bad design and all manufacturers that used plastic had issues. From there, the 3800 while you can google and find HG issues, the actual issues I have found are typically not HG. 3400's, very likely you have an HG issue. 3100's don't seem to have head gasket issues as much.
I am speaking from actual experience, doing compression tests, pulling heads and seeing failures or lack of a failure.
Plastic intake gaskets were clearly a bad design and all manufacturers that used plastic had issues. From there, the 3800 while you can google and find HG issues, the actual issues I have found are typically not HG. 3400's, very likely you have an HG issue. 3100's don't seem to have head gasket issues as much.
I am speaking from actual experience, doing compression tests, pulling heads and seeing failures or lack of a failure.
Not pointing figures at any one individual…but a general trend that I have observed. I have not worked on my 3.1 that much since it has been so reliable for 170,000 miles BUT have worked on cars for 30+ years-I just rebuilt the L-82 350 V8 in my 78 corvette myself and I mean all of it-450 HP-I know a few things about motors especially V8's…
Here's one for you….the machine shop owner that does my engine block work had a 3.1 with no rebuild that went…500,000 miles. The bone yards are full of 3.8's AND 3.1's with 250-300,000 miles on them. I have seen them.
Appreciate the clarification on the HG issue with 3.4's not 3.1's. The high performance engine shop owner who I consult with much on performance mods for my V8's and who was a GM factory field tech teacher for 16 years-he taught the GM mechanics on how to work on ALL GM engines including the V6 family-knows my SE 3.1 and feels that the 3.8 is a better engine than the 3.1 (no debate) but says the 3.1 is pretty darn good as well. I can assure all he knows more about the V6 engine family than just about most on this forum and owns a high performance shop modding cars for a living-big HP-like 500-900 HP-real HP.
Sven the Sexman
New member
Your last statement may also be somewhat false. I myself am ASE Master Certified, recently GM Master Certified, and long-time Audi/VW Master Certified...I TEACH this on a daily basis. While I admit I don't know everything, I certainly know a lot. While you may have seen or heard of 3100's lasting, my experience says otherwise. Everyone has to get lucky sometime though. I've seen Yugo's make it over 200000 miles...there's gotta be at least one to prove they aren't all crap. But, trying to tell anyone that a swapping a 3100 into a 3800 car is a good idea when 3800 engines are dirt cheap, have more power, get great fuel mileage (for a pushrod V6,) and more reliable seems to be kind of counterproductive.
To the OP, put back in what should be in there. Do all oil seals/gaskets while you have the engine out and drive the car. You'll be happy you did.
All I said was that the 3.1 is not a bad engine and that was confirmed by a 16 year veteran GM ASE Master Certified technician. I agree 100% with you that it is almost always best and easiest to put back the engine that was there-no debate. GM V8 and V6's are typically very good engines (pushrods or not) and generally get superb gas mileage compared to just about any engines of similar cylinder count and displacement.