Gm 3800 intake gasket diagnosis

Cousin’s husband has an ‘05ish monte carlo with n/a 3800.  It’s overheating.  I know intake gaskets are common on these, but what symptoms should i look for?  Never done one before 

My wife had a 1998 olds 88 I think, it had the seires 2 maybe of the 3800?

I did the intake gaskets on it, but I don't remember it overheating. Coolant in the combustion (white smoke), and a leaky plastic elbow were what prompted me to do that. I guess if it consumes coolant then it will eventually overheat.

If it is a 3800 and it is coolant, it is the plastic elbow.  The way it sprays out and gets things wet it will look much like head gasket seepage.  

Instead of $4 for another plastic, pay the $8 for the improved metal version!!!

Sample video: https://www.youtube.com/watch?v=3OH8Mx_YKHQ 

The intention is that the coolant cools this wheel:

I am always amazed that the elbow has no clamps.  Just one tiny o-ring to hold back all your coolant.  

Generally an easy job but I seem to remember there is a bolt that is not visible at the bottom of that wheel assembly that requires some "feel" to "see it".  

You will loose a tiny bit off coolant in this job so you will have to re-fill some coolant.  The 3800 has a handy bleeder screw on the top of the thermostat for bleeding off the air after filling with coolant.  Be sure to do this. 

I'd check to see what the condition of the dex-clog and coolant elbows are.  If the elbows are cracked and leaking replace with aluminum elbows, flush the system and replace with Prestone Green.

Series III motors should have aluminum manifold gaskets that won't get eaten by dexcool. I say should because '04 was the first year for the Series III engines and some had plastic gaskets that were leftover inventory, '05 should be a safe year for those.

My experience with a LeSabre 3800:  

About every 5-10 days it would report it was low on coolant and start to over heat.  Filling the coolant would solve the immediate issues.   I had no driveway puddling.  Underhood, the wetness was sort of shielded by the plastic engine cover.  The wetness began low.  I suspected HG and burning coolant.   I did not yet know of the elbow.  

What taking it apart showed was that the cracks in the elbow caused the engine to "steam off" coolant.  Never really leak coolant and never leak while at rest.  Only while driving and under engine pressure would the coolant come out of the elbow.   

My Buick's 3800 ended up having all the vanes corroded off the water pump. Is it losing coolant?

There's a lot of things that can cause overheating in these motors. Sometimes the LIMs will show up by one plug having a rather odd solid, but not sooty, black color on it.

Now that you mention it i did have to do the tensoner and elbow on FIL’s old lesabre.

i really don’t want to do this repair but he is driving (my new) subaru until the monte is fixed, and i want the subaru so i can do silly things like a light bar and roof basket and bigger tires.

I own 2 Grand Prixs. Possible locations of leaks are: LIM, elbows, crack in EGR. 

I'll come help you over the weekend if Carli will watch the girls play.  

In reply to John Welsh :

Going to talk to my cousin tonight.  I don’t know if it will get here or not, they’re 35 miles away.  It’s definitely a repair i’d much rather tackle with my full garage of tools than my track box that I keep in the truck.  

Temps are cool.  Bring water/coolant to fill along the way if really bad.  I'll bet it makes it.   Is it up near Euclid?  

Yep east 169th.  

Just got correction from her, it’s a 2003 which would be before the revised intake gaskets.  He bought it from a buy here pay here lot, and it’s had plenty of issues.  Personally I would have lit it on fire already but he loves blasting motley crüe with the windows down in his Monte Carlo after work.  

I'll bet he feels like a Nascar driver when he drives it.  His own Days of Thunder.  Ha. 

Is it Black?  Did he put a big #3 on the side?  

^ Didn't they come like that? 

It is black, no number 3

Ram50Ron said:

I'd check to see what the condition of the dex-clog and coolant elbows are.  If the elbows are cracked and leaking replace with aluminum elbows, flush the system and replace with Prestone Green.

Series III motors should have aluminum manifold gaskets that won't get eaten by dexcool. I say should because '04 was the first year for the Series III engines and some had plastic gaskets that were leftover inventory, '05 should be a safe year for those.

The main thing you get with the Series III is an aluminum upper manifold that won't erode/warp near the EGR passage, and fill the lower plenum with coolant.

As for the lower gaskets, I have seen them leak coolant into the engine but interestingly the main failure mode I saw in them was a vacuum leak after it sagged.  This was still kinda rare since the upper plenum usually failed WAY before that, and if you have the upper off, you might as well do the lower, and that damned elbow, and the little crossover gasket on the transmission side that for some reason does not come with the lower gasket kit and you have to order it separately.

Everyone I know keeps at least one of those in their toolbox as a kind of "private stock", because you always forget to specify to order the gasket for that little bugger until you have the manifold on the workbench.  And you can't otherwise get to that cover plate unless you remove the exhaust crossover.

If the problem is the elbow, you can replace that with common tools no problem.  The usual assortment of 3/8", 13mm, and 15mm sockets and wrenches.  Life got real good when I got stubby Gearwrenches, makes getting the alternator off much easier.

The lower intake manifold requires a 1/4" drive swivel socket.  Since they thread into the heads, the bolts are SAE and have a 3/8" head.  I only have metric 1/4" drive sockets so I just use a 10mm and tell it to not look suspicious and maybe the bolts won't notice.

(err, I MAY be thinking of the 3100/3400.  Can't remember if the 3800 has bolts under runners or not.  I know there are two bolts hidden inside the plenum that are usually covered with oil sludge and a puddle of coolant so you can't see them)

Knurled. said:

(err, I MAY be thinking of the 3100/3400.  Can't remember if the 3800 has bolts under runners or not.  I know there are two bolts hidden inside the plenum that are usually covered with oil sludge and a puddle of coolant so you can't see them)

You're probably thinking of the 60 degree motor. When I changed the LIM gaskets on a supercharged 3800, all the bolts were readily accessible, at least after you removed any sludge hiding them.