3.1 v-6

[joejenkinsglass]

I may have some serious issues with my dd cooling system. Its a 97 malibu. What I am wondering is if a 3.4 would fit in its place? This is not worth alot so if the heads are shot and not an easy (swap) fix probably be sending it down the road.

[Smittro]

I may have some serious issues with my dd cooling system. Its a 97 malibu. What I am wondering is if a 3.4 would fit in its place? This is not worth alot so if the heads are shot and not an easy (swap) fix probably be sending it down the road.

Yes. A 3.4 OHV will fit in the 3.1's place but there's more to it than that..

What's the issue with the 3.1? Codes?

[joejenkinsglass]

The heat was working, but only some times. I burped the system and no change. Then I replaced the rad cap and again burped the system. It seemed to fix it for almost a week. I did put a new t-stat in too with no change. Tonite changed out the water pump and filled with coolant again. I have no water in the oil and no smoke so seems the head gaskets are fine. I am hopeing it was the water pump. I also swapped the rad cap again cause it wasn't holding pressure again. If I were to put in the 3.4 what other than wiring would be an issue? The current 3.1 runs great but if it is infact heads I don't know if its worth fixing a motor known for head problems. Of course suggestions are welcome.

[Smittro]

The heat was working, but only some times. I burped the system and no change. Then I replaced the rad cap and again burped the system. It seemed to fix it for almost a week. I did put a new t-stat in too with no change. Tonite changed out the water pump and filled with coolant again. I have no water in the oil and no smoke so seems the head gaskets are fine. I am hopeing it was the water pump. I also swapped the rad cap again cause it wasn't holding pressure again. If I were to put in the 3.4 what other than wiring would be an issue? The current 3.1 runs great but if it is infact heads I don't know if its worth fixing a motor known for head problems. Of course suggestions are welcome.

Not a whole lot really. You can adapt the 3.1 harness and PCM to work with 3.4 and vise versa.. Almost plug and play..
That is of course provided the engine is out of a FWD car/mini van from 97-99.5 model years..
Most of the sensors are indentical from 60*v6 to 60*v6 (domestics only and except cam sensors)..
Hardest part is you may have to use your 3.1 timing cover so your accesories will be in the same spots as they were on the 3.1..
Not hard, it's a dirrect bolt on but tedious to switch everything over..
Many do a 3.1/3.4/3400 heads/cam/intake change over while their in there (if it does need heads)..
It's nearly a 30hp bolt on..lol

Head problems??
You do know that an FWD 3.4 OHV is an FWD 3.1 with a slight (+) bore right..
I've heard or plenty of LIM gasket fails but not too many head issues..
No smartass intended.. Head failiers do happen..

Purging all the air out can be a pita on the 660's. I'd also check that the heater core is'nt pluged up..
Replacing the water pump was'nt a bad idea, but you'll still have the same no heat issue if all the air is'nt out of the system..

[joejenkinsglass]

Yes I know the 3.4 is similar. From what little I have heard is its just a better design. I am not after more power, just dependability. The car seemed fine today I am thinking it was a bad radiator cap. I will report back either way.

[Smittro]

Yes I know the 3.4 is similar. From what little I have heard is its just a better design. I am not after more power, just dependability. The car seemed fine today I am thinking it was a bad radiator cap. I will report back either way.

The FWD high feature 3.1 and 3.4 OHV are the same design.. Same crank, same rods, same stroke..

Everything from a (domestic) 97-99.5 3.1/3.4 is interchangeable.

One just has a larger bore but the blocks are identical as well..

The RWD 3.1/3.4 is different.. RWD 660 cars/trucks have a different crank and a different stroke, head combo, and is not a high feature..

Hope it works out for ya..

[joejenkinsglass]

ef me I am almost certain I have a blown head gasket. Its driving me nuts. No water in the oil, no smoke. It just has too much pressure in the cooling system and no visible leaks anywhere other than out the radiator cap. Its going through about a half gallon everyday (lately) about 80 miles. Oh yeah heat still comes and goes.

[Smittro]

ef me I am almost certain I have a blown head gasket. Its driving me nuts. No water in the oil, no smoke. It just has too much pressure in the cooling system and no visible leaks anywhere other than out the radiator cap. Its going through about a half gallon everyday (lately) about 80 miles. Oh yeah heat still comes and goes.

Hmm well I guess you could always pull the heads and see..

The 2.8's used to have an issue with cracking between the valve seats..

Could be your issue too (not as common on the 3.1 but possible) if there was hot spots developing..

This could also cause an overly presurized cooling system as well.

It takes longer to get the intakes off then it does to pull the heads and replace/regasket them..

I will gladly help with any questions you may have, let me know..

[TLS_Addict]

Not to ask a dumb question but why not a junkyard 3.1 to just do an easy swap?

Many of my friends have had issues with the 3.4s. They clattered and one of them blew up and the other got rid of his before it exploded. All of my friends who had 2.8s (me included) and 3.1s and never had any issues. Maybe dumb luck? One of them was a Camaro and it was just junk.

Even the 3.4s I have test driven felt like crap.

[Smittro]

Not to ask a dumb question but why not a junkyard 3.1 to just do an easy swap?

Many of my friends have had issues with the 3.4s. They clattered and one of them blew up and the other got rid of his before it exploded. All of my friends who had 2.8s (me included) and 3.1s and never had any issues. Maybe dumb luck? One of them was a Camaro and it was just junk.


Even the 3.4s I have test driven felt like crap.

The 2.8 iron head was just used as an example of a problem that sometimes happened to the 660's..

Except he's talking about a high feature..

In the past 20 years I've had all types the 660's ever made.

Never once have I seen what you're discribing..

Not being a dick here shit can happen..

Anyways, there's a difference between a high feature and an iron head..

High feature 3.4 was drived from the 3.1 high feature not the 2.8,3.1, iron head..

just my .02

Junk yard is always an option for sure..

[TLS_Addict]

The 2.8 iron head was just used as an example of a problem that sometimes happened to the 660's..
Except he's talking about a high feature..
In the past 20 years I've had all types the 660's ever made.
Never once have I seen what you're discribing..
Not being a dick here shit can happen..
Anyways, there's a difference between a high feature and an iron head..
High feature 3.4 was drived from the 3.1 high feature not the 2.8,3.1, iron head..
just my .02
Junk yard is always an option for sure..

I just said junk yard because he sounds like he is going to do it himself. That way if the engine is junk they usually will give you another one and pretty much all he would be out is his time. I know thats how the junk yards around here work anyway.

The 2.8s I am talking about are the ole ones from 87-90ish. My friend and I both had Z24 5-speeds and they ran great and never had any issues up to over 150k HARD miles on each. lol Mine was an 87 and his was I think an 89.

He then got an Alero with the 3.4 and it blew up after it started making top end noise. The dealership took it back and gave him a different car because he had the problem documented with them. Then a friend of mine had a Camaro with the 3.4 and that would burn a quart of oil in less than 2k miles and most of it was highway miles so low rpms. When my dad was looking for a beater we drove a 3.4 alero and again, the top end was clattery and it seemed gutless. My best friend had a 99 Grand Am GT and even with 60k miles it clattered, got horrible mileage (in the low 20s), and seemed to be down on power.

Just hate to see the OP have a lot of issues with it being just a DD, and an older one at that.

[joejenkinsglass]

Thanks for the comments/recomendations. I did find one 3.1 for 650 bucks, it has about the same miles as mine. Other than machine shop bill for the heads parts are around 150 I will do this myself (no need for a shop). I would rather just swap the whole motor if I could find one cheaper.

[blackSS01]

I have owned 3 3.1L motors and they tend to have intake gasket problems. Haven't read the responses but maybe you have a lower intake gasket leaking externally

[joejenkinsglass]

I have owned 3 3.1L motors and they tend to have intake gasket problems. Haven't read the responses but maybe you have a lower intake gasket leaking externally

Wish that was the problem, but the cooling system is getting too much pressure. That tells me heads or head gaskets. Heat stops when coolant is blown out.

[joejenkinsglass]

Why is it that the 3.1 is so expensive(compared to others) I came across a 3.5 70k miles for $299 plus $150 shipped. I doubt it will fit though. ahhhhh

[Smittro]

Why is it that the 3.1 is so expensive(compared to others) I came across a 3.5 70k miles for $299 plus $150 shipped. I doubt it will fit though. ahhhhh

Well believe it or not the 3.1 high feature is a somewhat saught after engine because it came in so many vehicles mostly.

The 3500 will bolt up to your setup but you'd have to change quite a bit to make it fit/work..

I honestly would try to get to root of what's wrong with yours and maybe repair it if it can be repaired..

[blackSS01]

That and the 3.1L besides intake gasket problems tends to be bulletproof. All my 3.1L motors together had damn near a million miles on them with no issues when I got rid of them. Its an amazing little engine. I would love to turbo my current 3.1L Corsica

[Smittro]

That and the 3.1L besides intake gasket problems tends to be bulletproof. All my 3.1L motors together had damn near a million miles on them with no issues when I got rid of them. Its an amazing little engine. I would love to turbo my current 3.1L Corsica

Call McClearon(sp) they did it once..

I can dig up specs if you want to get silly..hehehe

[blackSS01]

Call McClearon(sp) they did it once..

I can dig up specs if you want to get silly..hehehe

I can't afford that shit when I can't afford tires for my beast

Hoping my business will be up and on its feet in the next 2 years

Then crazy toys come

[Smittro]

That and the 3.1L besides intake gasket problems tends to be bulletproof. All my 3.1L motors together had damn near a million miles on them with no issues when I got rid of them. Its an amazing little engine. I would love to turbo my current 3.1L Corsica

The 3.1 was released in 1990..

The upper valve trains where uber noisey on cold fireup from the day they were new but quieted after heat up..

GM made some changes for the 91 3.1's and the rest is history..

Aside from the obvious GM mess ups on gasket materials. It's a good engine..

75-80% of the troubles folks have with them is due to poor mantainance, or folks just not understanding/carring about it..

*That is Not dirrected @ anyone personally..*

Thousands of folks get the dreaded "air pocket" and most prolly are'nt aware that they have it.. Traped air in the (high feature 660 only) has been the cause of many if not most of the 660 troubles.. That stupid air pocket can ruin a perfectly good engine (water pump too high), which gave the 3.1 most of it's bad rep as well.. Thats why the 3.4 high feature got a newly designed water pump housing/timing cover.. They moved the water pump to be more inline (3-o'clock) with where it would be on most engines instead of @ 1-2 o'clock (cam shaft being the clock center point) possition on the earlier 660 high features. This helped with the air pocket issue but did'nt quite solve it.. This is why there is a bleeder valve on the upper rad hose..

To the OP upon further consideration..

If your car is'nt equiped with a bleeder I would Highly suggest to anyone to get one and place it inline on the upper rad hose..

The "trick" is to start the engine and let it get up to temp..

(BE CAREFULL WEAR EYE PROTECTION)

Then open the valve (IMPORTANT) ever so slightly till it hisses and coolant begines to flow steadily..

Make sure there's enough coolant in the rez to perform the proceedure..

This will need to be done a couple of seperate heat cycles..

I'm willing to wager this may solve ALL your problems and your heat will return..

I'd give it a try before yanking the engine..