Help with an 02 malibu

Hi, I've got a 02 chev malibu and a week ago found a darker layer of oily sludge on top of my coolant tank. I've read/heard about gaskets but the symptoms seem different enough to post this (no whitish mixed look, in coolant or oil, no overheating, no spills, no jelled chunks).

I've got the coolant flushed and will be checking the transmission fluid level and colour (maybe take it to get checked for coolant?). So far no more oil layer on the coolant, will repost when ive checkd the tranny.

Any suggestions?

The coolant can get a little dark residue after many miles. It's almost a certainity that your lower IMG is leaking or is on the verge of leaking unless it has been replaced before. Does your coolant level drop any over time?

I agree with the above post.

A likely (but not asssured) source is a failed lower intake manifold gasket. A chronic issue with the engine, typically at around the 7 year/80K mile point, give or take. Our '02 went about a year ago. Other symptoms you might see include a gradual loss of coolant, perhaps an apparent gradual increase in oil level, and maybe some coolant sitting in recesses on the engine under the throttle body. You might find some coolant under the oil in bottom of the oil pan, and the oil might start to look a bit cloudy. Give it a close visual inspection and monitor the situation closely. See the sticky thread on the intake gasket for more than you ever wanted to know.

The whitish milkshake and overheating would likely be a later on symptom. You might find some coolant under the oil in bottom of the oil pan, and the oil might start to look a bit cloudy.

When was your last coolant change? Did you use Dexcool or other coolant?

Just had the coolant changed bout a week ago. so far Ihavent noticed any symptoms returning, and I believe the coolant is universal (yellow).

Have to say Ive gotten alot of very adament suggestions that dexcool is the problem or that its a head gasket, thou the last one mostly before they got the whole story.

thanks for the respone on one of my first posts btw. ill update it as the work gets done.

I hate to say this after you just got the coolant flushed. First I do not think the dark residue was necessarily a sign of a huge issue, and I'm no Dexcool hater by far. But the truth is if you have the original or original style replacement nylon lower intake manifold gasket it is flimsy to begin with and is also just not compatible with the 2-EHA organic acid technology (OAT) that I believe most or all Dexcool brands contain. If you had the Felpro replacement gasket, Dexcool would probably not be a problem because I believe that gasket is compatible, and as far as I know the original headgasket are compatible with Dexcool. Another problem with most Dexcools is if the coolant drops too much, like from a leak, and air gets in the system Dexcool doesn't tolerate that very well.

Here's the problem, most all of those universal yellow coolants from Peak and Prestone etc are Dexcool clones with 2-EHA. Peak does have a universal coolant called Global Lifetime or possible Professional Liftime at Pepboys that is non-2-EHA and of course they also have old-fashioned Green inorganic acid technology. Another option is Zerex green and Zerex G-05. I prefer Zerex products and Peak Global.

My opinion is if you have the flimsy original gasket, getting all of the Dexcool or dexclone out and putting in Green, Peak Global, or Zerex G-05 will buy you some time before the gasket starts leaking or if it is already leaking, leaking worse over time.

Hey thanks manic. From what I'm hearing I guess the coolant in my tank is probably organic (and bad for my gaskets), and that unless I find another obvious problem the gasket has a slow leak that the coolant change wont help. Also wish that GM got it together and did some testing before several years of incompatible fluid/sealants. That said I like the way my malibu drives and gasket problems aside Ive heard the engine should last and run well (reason I didnt buy a focus ect)

That said I dont kno what gaskets are in as it was bought used awhile ago. Have to call the shop to check what coolant but Id assume prestone, could see they had the logo around. do you know what shops usually carry peak global or green universals, havent seen any around.

Thanks again for the reply. got called into work n had to cancel fluid so Ill post tranny fluid check n any other work i do results next week

Most likely you got some version of Dexcool or a clone. Yeah those engines are pretty good if you work a few bugs out and change the LIMG.
I don't mean to cause more alarm but I bet the coolant you have is a Dexcool and Dexcool will cause the original nylon gasket to leak faster. Some of these engines especiallty around '02 had iffy camshafts and the leaking manifold gasket caused the cam to sieze and ruin the whole motor.

I don't know of shops that carry Peak Global but imagine some do since it is advertise as a universal and non-2EHA coolant. I'd imagine more have Green, and some should carry G-05 since it is required for Ford, Chrysler and many European models.

I think if you intend to keep the car a long time, it'd be worth your trouble to find out if your gasket is leaking and either replace the gasket now and then it'd probably be optional to switch to one of the coolants I mentioned, or if you aren't going to replace the gasket right away at least just switch coolants and change your oil regularly.

I posted in another thread in the Malibu forum I think, about the leaky gaskets, oil analysis etc. I don't know if you seen it.

I like the oil analysis idea and the websites sound like theyll give some good info on whats next. I have to ask what might be a dumb question, assuming its done with the car off, wont the coolant preassure test push coolant into whatever fluid is leaking into the coolant now? never done it but im probably starting with whatever oil test (theyve got a few) they suggest for coolant n general engine condition.

ps. transmission check is good. oil and coolant still look good.

I like the oil analysis idea and the websites sound like theyll give some good info on whats next.

Yeah I would recommend going with oil analyzers. If you have any questions or once you get your oil analysis results back, I can help you interpret the results if you want. With Oil Analyzers since probably you are a "non-preferred customer" you'd want oil test kit Kit01, Kit02, or Kit06 under the non-preferred pricing. They are all the same just postage prepaid or not. If you get Kit06 and buy postage yourself at the US post office you can save some money since it only costs about $2-3 with delivery confirmation. If you are not in the US and in say Canada I'm not sure how much postage would be but they have a lab in Canada and provide the mailing address you can send your sample to. Just order your kit and once the bottle comes you just fill the sample bottle as you are changing and draining your old oil.

http://http://www.oaitesting.com/prices_automotive_fleet.htm




I have to ask what might be a dumb question, assuming its done with the car off, wont the coolant preassure test push coolant into whatever fluid is leaking into the coolant now? never done it but im probably starting with whatever oil test (theyve got a few) they suggest for coolant n general engine condition.

ps. transmission check is good. oil and coolant still look good.

Well if your transmission fluid is good and doesn't have coolant in it then a I doubt you have any oil actually in your coolant. About the only other place coolant can get pushed into is the engine oil. The thing is that will happen anyway if there's a coolant leak since the pressure tester doesn't pump the pressure much higher than the coolant gets while engine is running. The idea is to be able to pressurize the system without having to have a hot and noisy engine running so you can more easily check for coolant leaks or sounds of pressure escaping from the cooling system.

Oh yeah I wanted to add what brand of motor oil do you use? If you use brands besides Pennzoil and Quaker State, many of them contain sodium as an oil additive which can mask if sodium is in your oil from coolant or from an oil additive. But if you are not using an oil like Pennzoil or Quaker State you can still do the oil analysis no problem because for one thing they will also check potassium levels in the old oil which is another marker for coolant contamination.

yeah I think mobil extra milage was in from the last oil change. didnt seem like an issue at that point, Ill remember that for future oil changes thou. Im assuming no oil is better/worse once its in coolant and sliming the rubber and plastic tubes.