i have a 99 legeacy wagon 2.5 which had its head gasket redone around 60k. im now a little under 90k(so 30k on the new gasket). i added a half a bottle of coolant conditioner right after the gasket was redone(about a year ago). on the bottle it says to add a half bottle (for 4 cyl.) once a year to ensure protection. so the other day i added the other half of the bottle to the coolant and recently took a trip about 180 miles away and on the way back i noticed a few times for about a min. only the car smelled like it was burning oil and then it would go away. i talked to a guy at work today who knows his stuff(i really dont) and he said that coolant conditioner can cause your oil to turn to sludge and then start to burn off. so today i called a local garage to talk about flushing/draining and filling the coolant. i told him of why i had the coolant conditioner in the car in the first place and he said that if he flushes the coolant and i have a bad or weak head gasket that it will go right after the coolant flush.

so what im asking is for your skilled opinions on what i should do with my coolant issue. flush or just drain and fill?? i am taking the car to the garage in about 4hrs. any help would be great.

ooh and btw, if i have them just drain and fill the coolant will that drain only whats in the radiator or will it get the engine block coolant as well??? like i said i dont really know cars much past changing my oil and other simple fixes.

Unless your coolant is due for a flush I would hold off on that. Instead, Iwould have a block check done to see if exhaust gases are getting into the coolant. Is is a cheap test to do and you will know what is happening. If the test is negative then you should have no problem.

 

Your timing belts may be due for changing.

would i need to go to subaru to get the block test done or can somewhere else do it besides the dealer?

Most shops should be able to this.

To answer your other questions, a regular drain and fill would not drain the coolant from the engine block. My understanding is that it would drain approximately 70% of your coolant.

Mine is not an expert opinion and should be viewed as such. IIRC, the 2.5 in the 99 Legacy is still the DOHC.

 

Your engine is prone to leaky head gaskets between the cylinders and the coolant with exhaust gasses leaking into the coolant, wreaking havoc with the cooling system. The coolant conditioner will not help in this situation. It will only help to plug leaks where the coolant is leaving the system.

 

I can see no reason why flushing the cooling system would have any effect on your head gaskets. If flushing were all it took to blow HGs, they'd have blown long ago.

 

I can also see no reason why conditioner in your coolant would turn your oil to sludge.

<<i have a 99 legeacy wagon 2.5 which had its head gasket redone around 60k. im now a little under 90k(so 30k on the new gasket). i added a half a bottle of coolant conditioner right after the gasket was redone(about a year ago). on the bottle it says to add a half bottle (for 4 cyl.) once a year to ensure protection.

coolant conditioner from subaru is only for the External coolant leak. It will not fix the internal leak. it sounds to me that you have the internal leak.

 

<< i talked to a guy at work today who knows his stuff(i really dont) and he said that coolant conditioner can cause your oil to turn to sludge and then start to burn off. >>

 

obviously, he doesn't know subaru's. coolant and oil don't come into contact with each other in a healthy engine. if he means the internal leak, then it will eventually ruin the oil. maybe thats what he means.