01 regal foam in coolant reservoir

[sjonesy2]

hello, my wife drives an 2001 buick regal ls with the 3.8L motor. The low coolant light comes on when the car is first turned on but goes off after about a minute (it stays on after all other lights on the car go off on the dash). I can disconnect and reconnect the battery and the light will stay on for about 30 minutes and the more its drove the less it stays on until its at the point to where its at now. the bleeder valve has a small leak and i seem to have been unable though i bought new bleeder valve and tighted it down pretty good on the thermostat housing to stop this leak. its not bad but you can see the coolant has made a little stain on the housing. The only reasons i mentioned these problems is because the might relate to a new problem i found the other day when checking my fluids. The coolant reservoir has some foamy looking stuff in it. i took a paint stiring stick and placed it into the resevior to get a better look at the top of the coolant and its obvious it has some type of oilly like mixture on top of the coolant. i called a friend of mine which is a mechanic and he said take a towel and try and get what you can out and check it again to see if it comes back in about 30 days. i waited less than a week and it has already come back although i was unable to get it all the first time and its not as bad as it was the first time its obvious it has started to come back already. several months ago now, i accidentally poured a little transmission fluid (i looked at the wrong container while it was dark and i was checking my coolant level after replacing the bleeder valve because of a low coolant light that stayed on constantly and my brother-in-law accidentally breaking the bleeder valve) into the radiator. i then immediatly flushed the radiator just with water and didnt notice between now and then that there was any foamy stuff on top of the coolant in the resevior. there is no foamy residue in the radiator itself just the reservoir. i intend on buying an actual flush kit and flushing my radiator this weekend. i have been told by my mechanic friend that this could be a intake manifold gasket and it would be about $200 to replace parts and labor. i do not have any overheating problems, although it has been very cold here lately. i really dont know what to do, if a stop leak of some sort would help, flushing the radiator if that would solve my problem, or if i will have to replace the intake manifold gasket. any help will be appreciated and thank you in advance, sjonesy2.

[BNaylor]

What is your current mileage? Have you checked for coolant loss? Are you still using Dex-cool? It is not uncommon to see oily residue or sludge in the reservoir but it could indicate an issue with the UIM and/or LIM gaskets.

[sjonesy2]

i have about 150k on car and i am not loosing coolant. i am sitll using dex-cool, is that a bad thing? if it is one of those gaskets you suggested does it need replaced? thanks sjonesy2

[BNaylor]

The first signs of a bad UIM or LIM gasket will be either an external leak or unexplained coolant leak where coolant is burned via combustion so if you are not having to refill the reservoir or radiator direct then the intake gaskets may not be an issue.

How old is the Dex-cool? The stuff is only good for 5 years or 150K miles, whichever comes first and may be breaking down. The best thing to do since you accidentally added Dexron ATF into the cooling system instead of Dex-cool is to get the cooling system thoroughly and properly flushed. Then resupply with new Dex-cool or an aftermarket extended life coolant. Afterwards do another bleeding to ensure no air is in the system.

Another way to test intake or head gaskets is to run a cooling system leak down test.

[sjonesy2]

I'm not having any smoke or any leaks that i am aware of. The dex-cool is not very old, i just replaced and and bought new that day or the day before a few months ago (probably around 6). When I added the transmission fluid I did flush it out with water, but I did not let it run any time so I probably didnt do it right. I still intend on buying a flush kit today and flushing this weekend. I have some dex-cool that has been in my storage building since that last time I flushed it (probably about 6 months) would that be okay to use or should I go buy new.

What is a system leak down test? How do you do it? Thanks.

[BNaylor]

As long as the Dex-cool was in a closed container I see no reason why it can't be used. Why waste money since the stuff is more expensive then regular aftermarket coolants. I have Dex-cool that has been sitting in the original container about a year old and would not hesitate to use it.

We have a flushing procedure posted at our Buick Tips & Maintenance section you can use as a guide. See link.

Click here

On the cooling system leak down test a special adapter/fixture is connected to the radiator and the system pressurized and then the decay monitored which may reveal intake gasket problems or some other leak.

[sjonesy2]

thanks again for the quick response, do you think i need to do the leak test? if i flush radiator as described and foam comes back what does that mean? how long would it take to reappear if it was going to? and this may sound simple but how do you check and make sure the thermostat is open? thanks so much sjonesy2.

[BNaylor]

You're welcome.

I would do the flush first and then go from there. You can tell when the thermostat opens by watching the engine temperature at the temp gauge at the IP. If it doesn't open or open at the right time then your operating temperature will be high, probably above 1/2 scale or more on the IP gauge. Also, the PCM module will trigger a P0128 DTC if the thermostat is not opening properly or too slowly. The other scenario is the thermostat is staying open so engine warmup will take longer but the IP temp gauge will read low around 1/4 scale or less. The other way to test a thermostat is to remove it and put in into a pan of boiling water on the stove with a temperature indicator and see when it opens. Stock should be fully open at 195 degrees.

[sjonesy2]

I intend on flushing the radiator monday. I have already bought the stuff today. I will try and report back in about a week about what happens after the flush. My wife drives it about 300 miles a week so we should find out pretty quickly if there is going to be anything come back. Thanks for the help

[sjonesy2]

hello again. I flushed it today and it looked pretty clean. the reservoir was pretty dirty but the coolant looked really really clean. im going to let my wife drive it and periodically check the fluids and probably post again either sat or mon. it will have been drove by then about 240 miles. thanks for help. steven.

[sjonesy2]

Hello again, I checked yesterday and will check again more thoroughly tonight. Didnt see much but not for sure and it was very cold and i was in a hurry. will post again tomorrow. thanks

[BNaylor]

Thanks for the feedback and updates. About all I can suggest is monitor your coolant level over a period of time just to make sure you have no intake gasket issues. Good luck!

[sjonesy2]

Hello, sorry for the delay been busy and havent had time to post again. I checked it again and didnt see anything in the coolant. I will continue to keep an eye on it about weekly for a little while and make sure there is nothing that shows up. If something does I'll post back on this thread and update you. I appreciate all your help. Thanks, sjonesy2.

[sjonesy2]

thank you for all your help i checked it again lately and it was fine. I appreciate all your info and your help. Thank you again. sjonesy2

[BNaylor]

Thanks for participating in the forum, the feedback and you are welcome. If you have any future issues you know where to come. Good luck!