2007 Buick Allure 3.8L coolant issue


Engine:Series III 3.8L

The car is losing coolant and the local garage can’t find anything wrong.

Here’s the symptoms of the issue, the temperature gauge climbs over the half mark on the needle to where the fans are going crazy and the car needs to be turned off letting it cool down to prevent any damage.

We also keep filing the overflow tank too.

The local garage did a coolant test and found nothing wrong, they did a freeze test among others. they said the head gasket is fine, they said the water pump doesn’t leak. They even ran the car on the hoist and nothing was leaking.

We are hoping the local dealer can help, they are going to use the dye method to help find the leak something the garage didn’t use.

Didn’t GM fix the Series III 3.8’s with the intake manifold issue?, there’s no coolant in the oil either? I personal think it’s the water pump leaking or the heater core inside the car. We used to always hear a wish wash noise in the passenger area but that has now stopped with the over heating issue above started.

We are just lost on the issue and the near overheating concern.

hoping some members can lend advice.


I would find a good independent mechanic and have the engine completely checked. That coolant is going somewhere and the cause needs to be found before the engine life is impacted. The dealer may be able to find the problem but it’s going to cost you more. That’s why I suggest seeing an independent mechanic.

Like missileman, I would suggest that you take the car to a different mechanic, with special attention being given to the water pump and the intake manifold gasket.

If the heater core was leaking, you would smell the characteristic odor of coolant, and your windshield would have an oily film on the inside. If you don’t have an odor or an oil film, I think that your heater core is not the source of the problem.

Incidentally, for those who don’t recall a Buick model named “Allure”, that model is sold in Canada and is the same as the Buick Lacrosse which is sold in The US. It seems that the Lacrosse name conjures up some…less than desirable…imagery in French Canadian slang, so GM decided to use a different name for this model in Canada.

Missileman we did take the car to a independent shop and paid $300.00, that’s why this is so troublesome. I’d rather the dealer and get you need "this and that’ speech for $300 and the problem was found.

VDCdriver we don’t have any odor in the car or oil film issue, the defrost works fine too.

About the Intake manifold gasket, so they never did fix it? I was reading it’s sleeved with metal now to prevent that issue, also read about a elbow issue coming of the water pump and from the back of the engine to. Another member had the same issue

Not a fan of the Eric forum, both my accounts are locked from signing up and even emailed admin about the issue.


I checked the tranny fluid and it’s pink, also the oil and doesn’t have an odor either.

I’m not sure how to check the water pump? can I buy dye myself to check everything before tomorrow.

Knowing how much coolant you are losing and the actual engine operating temp would be helpful.

A couple of thoughts:
Possible leak in reservoir if reservoir coolant level stops dropping at a certain point.

Fans running at the highest speed doesn’t indicate engine overheating.
If they continue to run and engine temp increases above normal operational temp then there is overheating.


“I checked the tranny fluid and it’s pink”

It should be RED, not pink

If the transmission fluid is pink, it might be contaminated with coolant. That would mean the transmission cooler . . . which is inside the radiator . . . has failed, causing coolant to mix with the transmission fluid

If that is the case, not only do you know where your coolant is going, but your transmission will suffer damage

"I’d rather the dealer and get you need “this and that’ speech for $300 and the problem was found.”

Can you clear this up? This sentence doesn’t make any sense to me.

I think the op means an independent shop charged him $300 and didn’t find it and that he’d rather go to a dealer to at least find the problem.

I myself have had good luck at dealers who are factory trained and see the same cars over and over so that’s where I’d head. That link said they found the leak and it was the elbows by the tensioner so that sounds like a likely cause. Also I’ve used Dexcool with no problems. I had new put in though after four years and you have to be super careful not to introduce air into the system.

...you have to be super careful not to introduce air into the system.

How do you not introduce air into a system you’re draining and refilling?

You have to make sure the system is properly bled which is why I left it to a pro.

Even though the Allure is similar to a Lacrosse, I knew some people who tried to sell a used one in the US, and were told they couldn’t due to the lack of safety testing of the Canadian model. Seems odd, since they were essentially the same car.

Another odd thing, why did they name it the Lacrosse in the US? Are they planning to name the next model Football or Basketball?

@VDCdriver Do they play Lacrosse in Canada? What’s the meaning of the word up north?

“Do they play Lacrosse in Canada? What’s the meaning of the word up north?”

I don’t know whether or not they play Lacrosse in Canada, but as to the meaning of that word in Canada, here is some info from the Wikipedia page on the Lacrosse:

It was originally sold as Buick Allure in Canada, as “crosse” is a vulgar word that can mean either “rip off” or “masturbation”, depending on the context, in Quebec French slang.

The game of Lacrosse was invented by Canadian Indians and adopted by French and English settlers. Canadian French has many slang words and expressions, even unfamiliar to the French in France.

Buick wisely chose a different name for the Lacrosse.

"You have to make sure the system is properly bled which is why I left it to a pro."

I currently have 3 GM cars with 3.8Ls in them (on purpose). I had them for many years and hundreds of thousands of miles. I have never had a problem with DexCool. Also, I find that changing coolant is fairly easy and bleeding the system is not difficult at all.

These cars all have a bleeder at the apex of the engine’s cooling system, it’s easy to access, and works very well. I’ve never had to re-bleed any of the cars and simply drain coolant, refill with the bleeder open as specified by GM, close the bleeder when coolant seeps out, and put the radiator cap back in place.

I usually pull out the coolant reservoir and clean it inside and out, which is also very easy to do on these cars. I think there’s just one 10mm nut holding them in place.


My problem was I couldn’t hardly see or find the thermostat housing let alone the bleeder. I wanted all the hoses and thermostat changed along with the coolant and wasn’t sure I could finish it all with the tight access. So just farmed it all out rather than taking the chance on getting it only half done with a partially filled system. Felt good not working on it myself for a change.