Salvaging the Old 3100

**ShadowSwept** · 03-28-2012

Okay, first and foremost; what if anything, can be used from a 3100 on my 3800?

Barring that, my old 3100 needs to be fixed. The most serious problem is that it's overheating. Badly. As in it might make it two miles before it's in the red and the computer limits the RPMs.
Checked coolant and everything. Oil looks fine but the oil cap does have a trace of milky white in one spot.

The engine has been replaced with one out of a Buick Century, because the last one blew a head gasket. Would rather not replace the motor again but it does need to be fixed. So, any advice?

**Fivefingerdeathpunch** · 03-28-2012

Bleed the cooling system??

Otherwise, I dont think anything 3.1 can work with 3.8

**dpzelenak** · 03-28-2012

nothing will work between the two,
find parts for an 3400 and put in the 3100(since there basically the same motor)
and plus the 3400 parts will be a little upgrade at the same time.

**ShadowSwept** · 03-28-2012

Originally Posted by dpzelenak

find parts for an 3400 and put in the 3100(since there basically the same motor)
and plus the 3400 parts will be a little upgrade at the same time.

Sounds like a plan... but what parts exactly?
I'm guessing it's a blown head gasket again (any other thoughts?). Is that as easy as it sounds- just changing a gasket, or is there a lot more to replace.

I don't mind doing hard work, as this car is out of commission and nobody's waiting on it, but I don't have the equipment to pull a whole motor.
So, can I get this thing running again on my own?

**ctracer** · 03-28-2012

im thinking its actually a blown Lower intake manifold gasket since you're leaking coolant. it's kind of a ***** to do. im like 95% positive you dont need to pull the engine to do this. nothing else NEEDS to be replaced i dont think.

**dpzelenak** · 03-28-2012

you call pick up a 3400 top swap(heads/intakes) for cheap
check out 60DegreeV6.com - Site News
lots of good info and theres a good "for sell" section to

**dsmuts** · 03-28-2012

It's probably the lim gasket. It's not fun to do but it's not the worst thing I've ever done.

**ShadowSwept** · 03-28-2012

I think I can handle that.
Now if there is water in the oil, is there anything else I need to check while I have the engine apart?

**Steel Armadillo** · 03-28-2012

Wait. Basic questions first, you do have water flow? The LIM could be freaking missing and it wouldn't cause it to overheat that fast. Check to make sure the thermostat is working (opening), the old pot of water on a stove with a thermometer and the thermostat in it has served me well in the past. And even if the LIM were that bad, you would see definitely see "milkshake" under the rad cap and milky white on the dipstick.

**ShadowSwept** · 03-30-2012

I'm pretty sure we just changed the thermostat, but I'll check. The last anyone messed with it they bled the air out of the hoses and filled it with 50/50. I just checked the oil the other day and it was fine except that splotch on the oilcap. It's been sitting for about three months now.