YACT: I need an expert on the GM 3800 Series II V6. *** Update *** Confirmed broken intake.

[FrustratedUser]

OK, I might have issues with the car. I suddenly started loosing coolant and I see no wet spots under the car on inside the engine compartment.

I've had this problem once before and then it was the upper intake manifold (made of plastic) that had broke and coolant were leaking into the intake and from there into the cylinders. Back then the 'check engine' light had come on indicating a misfire. This makes perfect sense. This progressively got worse and the amount of lost coolant was huge. I was lucky not to hydro lock the engine.

This time I lost maybe 3/4 quart in 5 miles so it's a big leak. Check engine light is NOT on (yet?).
I need a sure way to find out if it's a broken head gasket or if it's the intake again.

My plan for the weekend is to remove the throttle body and look inside the intake for puddles of coolant. Then I know for sure it's the intake again.

Update:
Removed throttle body and saw traces pf coolant.

 

[EatSpam]

You should have bought a Toyota. They were touched by His noodly appendage, doncha know?

 

[FrustratedUser]

:roll:

Way off-topic spam and trolling there dude.

 

[SilverTorch]

there is a plastic elbow connecting the water pump and the intake manifold, check that .... had that happen on both my 95 Bonneville and 97 Grand Prix.

 

[FrustratedUser]

Originally posted by: SilverTorch
there is a plastic elbow connecting the water pump and the intake manifold, check that .... had that happen on both my 95 Bonneville and 97 Grand Prix.

:thumbsup:

Will do.

 

[CrackRabbit]

Originally posted by: FrustratedUser

Originally posted by: SilverTorch
there is a plastic elbow connecting the water pump and the intake manifold, check that .... had that happen on both my 95 Bonneville and 97 Grand Prix.

:thumbsup:

Will do.

Usualy when that happens you will end up with coolant under the car or should be able to smell it burning off. My vote would be with the intake manifold or manifold gasket.
Have you checked the color and consitency of your oil yet?

 

[FrustratedUser]

I looked at the dipstick today and it looks normal. I also checked through the filler cap and can't see any milky oil.

 

[iamwiz82]

What about the radiator cap?

 

[FrustratedUser]

Originally posted by: iamwiz82
What about the radiator cap?

Nothing obvious there but I will check for steam.

 

[imported_Phil]

I don't know if this will be relevant, but when I was asking my mechanic how to tell if you have the beginnings of a head gasket failure, he told me that the blower would begin to stop producing hot air.

Like I said, probably irrelevant, but that's what he told me.

For reference, my car's a 1991 non-fuel-injected 1.1 Citroen.

 

[FrustratedUser]

Originally posted by: Phil
I don't know if this will be relevant, but when I was asking my mechanic how to tell if you have the beginnings of a head gasket failure, he told me that the blower would begin to stop producing hot air.

Like I said, probably irrelevant, but that's what he told me.

For reference, my car's a 1991 non-fuel-injected 1.1 Citroen.

I don't understand. What blower and what hot air?

 

[imported_Phil]

Originally posted by: FrustratedUser

Originally posted by: Phil
I don't know if this will be relevant, but when I was asking my mechanic how to tell if you have the beginnings of a head gasket failure, he told me that the blower would begin to stop producing hot air.

Like I said, probably irrelevant, but that's what he told me.

For reference, my car's a 1991 non-fuel-injected 1.1 Citroen.

I don't understand. What blower and what hot air?

The thing you turn on to blow air at you when you're driving?

 

[FrustratedUser]

Originally posted by: Phil

Originally posted by: FrustratedUser

Originally posted by: Phil
I don't know if this will be relevant, but when I was asking my mechanic how to tell if you have the beginnings of a head gasket failure, he told me that the blower would begin to stop producing hot air.

Like I said, probably irrelevant, but that's what he told me.

For reference, my car's a 1991 non-fuel-injected 1.1 Citroen.

I don't understand. What blower and what hot air?

The thing you turn on to blow air at you when you're driving?

Oh OK.
I still don't get how that would indicate anything else than a coolant leak. Thanks anyway.

 

[CrackRabbit]

Originally posted by: FrustratedUser

Originally posted by: Phil
I don't know if this will be relevant, but when I was asking my mechanic how to tell if you have the beginnings of a head gasket failure, he told me that the blower would begin to stop producing hot air.

Like I said, probably irrelevant, but that's what he told me.

For reference, my car's a 1991 non-fuel-injected 1.1 Citroen.

I don't understand. What blower and what hot air?

He is talking about the heater, when you have a failing headgasket or air getting into your cooling system often times your heater will not get hot due to all of the bubbles/ air in the system.

 

[RU482]

Originally posted by: Phil
I don't know if this will be relevant, but when I was asking my mechanic how to tell if you have the beginnings of a head gasket failure, he told me that the blower would begin to stop producing hot air.

Like I said, probably irrelevant, but that's what he told me.

For reference, my car's a 1991 non-fuel-injected 1.1 Citroen.

I had that exact thing happen last week, along with disappering coolant. Couldn't figure it out until one day I looked at the water pump and saw a small trickle coming from there when the car was warmed up. eplaced it and now the engine is noticably quieter, no coolant loss, and the heat works great.

1991 Buick Lesabre

 

[natto fire]

hmmm, I thought my friends having troubles with that engine was a rare occurence, but I guess it really is a horribly designed unreliable motor. Powerful, especially considering it is pulling almost 2 tons of car, but my friend and his dad have owned 3 Bonnevilles. They had major engine trouble on all 3, why they kept buying them is beyond me. The '97 blew the head gasket first, and then the intake manifold broke.
Anyways like it was mentioned above, if it is a head gasket then there will be coolant in the oil. It is very distinct looking, but it looks like you checked that already. It is sounding like the intake manifold again, but losing 3/4 quarts in 5 miles is a lot, smell the exhaust for that distinct smell of burnt ethylene glycol. You can check it while the car is running or not, if you combusted that much coolant in 5 miles, the tail pipe should still smell like burnt coolant.

 

[FrustratedUser]

Originally posted by: Captain_Howdy
hmmm, I thought my friends having troubles with that engine was a rare occurence, but I guess it really is a horribly designed unreliable motor. Powerful, especially considering it is pulling almost 2 tons of car, but my friend and his dad have owned 3 Bonnevilles. They had major engine trouble on all 3, why they kept buying them is beyond me. The '97 blew the head gasket first, and then the intake manifold broke.
Anyways like it was mentioned above, if it is a head gasket then there will be coolant in the oil. It is very distinct looking, but it looks like you checked that already. It is sounding like the intake manifold again, but losing 3/4 quarts in 5 miles is a lot, smell the exhaust for that distinct smell of burnt ethylene glycol. You can check it while the car is running or not, if you combusted that much coolant in 5 miles, the tail pipe should still smell like burnt coolant.

IMO the only bad thing with the 3800 is the plastic upper intake. The rest is great.

I had oil in the coolant when the intake broke. The symptoms only started yesterday afternoon so it's still early.

I will check everything suggested here.

 

[FrustratedUser]

I forgot to say the temps are still fine. Running at 185 - 190F. I have a 185F thermostat in it since my stay in AZ.

 

[SilverTorch]

Originally posted by: FrustratedUser
I forgot to say the temps are still fine. Running at 185 - 190F. I have a 185F thermostat in it since my stay in AZ.

Thats strange, if you are loosing coolant your temps would sky rocket after about 15 min of driving.

I do agree that the plastic elbow thingy is the only thing wrong with the 3800s, series I and II had the elbow, not sure about III.

let us know what it was.

 

[getbush]

In August the the upper intake failed on my 99 Regal with 60,000 miles. This caused the head gasket to blow. I wish I drove a Honda or Toyota, but the car is free for me to drive while in college, except gas, so who am I to complain?

 

[Minjin]

Compression test and leakdown test. Go from there.

Mark

 

[FrustratedUser]

Update:

I just took off the throttle body and looked inside the intake. It is now confirmed. The plastic intake is broken. I could clearly see a small amount of green coolant in there.

At least I caught it early this time.

 

[Grouchyoldguy]

Does your throttle body have coolant lines to it? I know my 4.8 is water cooled. I'm not familiar with the 3.8. Does the plenum (upper intake) have coolant lines going to it?

 

[Analog]

When you say throttle body, are you referring to where the flexible rubber air intake duct goes into the 'plastic' intake manifold? I guess you can kind-of look in there - or do you mean something else? Just wondering, as I have a '95 3800 in my minivan.

 

[Grouchyoldguy]

Originally posted by: yellowfiero
When you say throttle body, are you referring to where the flexible rubber air intake duct goes into the 'plastic' intake manifold? I guess you can kind-of look in there - or do you mean something else? Just wondering, as I have a '95 3800 in my minivan.

If I follow what you are saying correctly, the piece in between is the throttle body. The cable from your gas pedal connects to it.