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Radiator Flush

I took my old reliable 1999 Subaru Legacy Outback Wagon for an oil change at a local fast lube place. After changing the oil they talked me into an air filter replacement which I said yes to. Then they talked me into a radiator flush. I declined first but then after they offered it for $ 79.99 instead of their usual $ 99.99, against my usual good judgment, I said yes.

After they were done I drove the car to work. In about ten miles the engine-hot needle raced to the top, the heater stopped working. I called the shop, the mechanic said may be there were some air bubbles left. Bring the car back. They struggled with it for a few hours to no avail. Couldn’t figure out what was happening. So I asked the lube shop to call the local Subaru dealer, whose advisor said that the head-gasket is blown and the safety mechanism, whatever that is, turns the heater off as a safety precaution. You should not flush the radiator but drain the fluid and refill it.

Before I took the car to the lube shop there was no evidence of leaky or blown head-gasket. The car oil did not have white residue due to radiator fluid leaking into the engine oil. The car heater was working fine. The radiator fluid in the radiator was green. Not black or dirty.

The head-gasket repair is estimated at approximately $ 1800 – $ 2500.

The lube shop says that the damage is not their responsibility because the car is old and has 148,000 miles on it. This thing is common on Subarus etc.

What do you think the reason for the blown head-gasket? “Flushing” the radiator which is usually uses a pump? Or trapped air after the radiator was flushed and refilled? Or both?

Is it worth to get the car repaired or just get another car? Or should I try to pour some radiator leak seal compound in it?



  • Is the car running poorly or is the head gasket diagnosis given only because of an overheating problem?

    Offhand, it sounds like the fast lube erred in filling the coolant. The mistake you made was continuing to drive the vehicle while it was severely overheating.

    I would be very leery of a head gasket diagnosis fault that was given to you by a fast lube facility who got their information on a phone call from a service advisor at the Subaru dealer. Most service advisors are not sharp, mechanically speaking, and I have no idea what this alleged safety device is that the advisor refers to.
  • I doubt if the flushing caused any damage.

    Let's start with the oil change. You say you took it to a &#$* fast oil change joint????? That was your second mistake. The first mistake was not opening the owner's manual and following the instructions there about when and what maintenance your car needs.

    Those fast oil change places off cheap maintenance because they hire cheap - unskilled employees and then push them to get more work done in less time, just begging to have problems. Find a local independent (not a chain or a dealer (dealers usually do a good job, they just charge too much.)

    I can't tell you what condition the engine is in now, you should take it to that independent shop (Ask your friends and neighbors for someone they trust) and have them check it out. See what really needs service and what the current problems may be.

    Chances are the best bet from the stand point of your cost of car ownership is to fix or service as it should have been. You will know more after you have a real mechanic, not a oil change kid has had a chance to evaluate it in person. I suspect you will be best off having any needed repairs done and from then on make sure you keep up with all maintenance. The most expensive maintenance is that maintenance that is not done or done too late.

    Good Luck
  • Thanks ok4450.

    The Subaru dealer looked at the engine , where the car was later taken, and confirmed that the head-gasket needs replacement. I don't know how they check this without taking things apart. But that's what the dealer service dept says.
  • Did the temperature gauge make it all the way to the red? Subarus are, in fact, known for head gasket problems, and the leaks can present in multiple ways - not necessarily via poor running or coolant in oil, etc. It depends on the nature of the leak. But one thing that can get a head gasket to leaking is overheating. So its possible that the shop messed up on refilling w/ coolant. Thus the car overheated, thus the head gasket blew.

    But its possible that it was already leaking too. Do some internet searching on Subaru head gasket issues.

    Stop taking your cars to fast lube places.
  • Thanks cigroller.

    The temp needle never made it to the red. No more fast lube for me.

  • If the temp needle never hit the red zone then I think there's some chance you're looking at a coincidence. Nothing about flushing to cooling system alone could damage the head gasket, and for heat to blow it you'd have to over heat - as in get to the red.
  • If there was a lot of air in the cooling system there could be hot spots that might damage a head gasket without making the temp gauge go up to the red zone.
  • "If there was a lot of air in the cooling system there could be hot spots that might damage a head gasket without making the temp gauge go up to the red zone."

    Good point. That never is a good thing, and with the fragility of those Subaru head gaskets...
  • There are tests that can be done to determine if a head gasket failed or not and I assume the dealer did some or all of those tests. I apologize for assuming the dealer did not have their hands on the car based on the way the post was written. The point about service advisors still stands though..... :-)

    Subarus have been prone to head gasket problems but if there was no problem when you entered the fast lube and the problem surfaced 10 miles after leaving there it makes things a bit too coincidental.
    I have to think that someone did not get all of the air out of the system and allowed it to leave low on coolant.
    It could be that the fast lube model of hurry up and get it done did not permit the thermostat to open before handing the car back to you. This could have led to a low coolant level.

    The fast lube is likely at fault; proving it could be something else.
  • My first thought based on the description of the chain of events is that a clamp or drain cock was left loose and the car ran out of coolant. I also agree with ok4450's assessment of the service advisor. Most of these guys were at one time star used car salesmen who were moved to the service counter to move fluid flushes. If your heat stopped working, it was probably because you ran sufficiently low on coolant to have emptied the heater core. The bit about a safety device shutting off the heat in the event of an overheating condition does not make sense and is contrary to conventional wisdom to turn on the heater full blast if your car is overheating since doing so will draw heat out of the engine. This, of course, does not apply to air cooled engines, which your Subaru does not have, and I will stand corrected if someone else brings to my attention some way in which the heating and cooling system on a Subaru is different from other vehicles and running the heat while the car is overheating will in fact damage the engine.
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