Strong antifreeze smell

UK Bugeyes WRX 2002 It's driving me nuts trying to find out why I'm getting a horrible burnt antifreeze smell. No sign of a leak, the engine temp is spot-on and I'm losing half a cup of coolant a year, no more than that. No sign of trouble in the heater matrix...all dry and working. I have slightly overfilled the reservoir by a couple of inches but the pong was there before I topped up. The rad cap doesn't appear to be leaking either. Any pointers would be gratefully received. My local tech is stumped...me too! TIA

Clive

-C- Anything is possible if you don't know what you're talking about

Reply to
fourstring
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Do you smell it coming out the tailpipe?

Reply to
VanguardLH

Do you smell it coming out the tailpipe?

No, it's up front somewhere. No sign of a blown head gasket either. Just driven around to get it hot so the fan kicks in. Again, everything nominal and no steam or drips anywhere. I'm stumped. I appreciate your reply...thanks.

-C- Anything is possible if you don't know what you're talking about

Reply to
fourstring

We had a "leak" reported by a car shop (that we no longer visit). The called to say it would cost $1800 to replace the manifold gasket because of a leak. When asked where they noticed the leak, they could not elucidate (someone at the desk was calling, not the mechanic that worked on the car). With insistence, the leak was a puddle of coolant atop the engine in a recess. How'd the coolant get up there from a gasket leak? They couldn't answer.

We've had no spots on the garage floor or fresh spots anywhere we park. What got me thinking about where it came from is they said the radiator cap had to be replaced. Couldn't hold the pressure. Well, if coolant came out the cap while at speed then it would spray back onto the top of the engine. We replaced the cap. The engine compartment got washed. There is no sign of a leak. The cap cost $8, a lot cheaper than the shop's proposed $1800 for a gasket.

That the radiator cap doesn't appear to be leaking doesn't mean it can handle the pressure. If it leaked which would be at normal or high engine temperatures, you're also probably moving down the road or highway and blowing what leaks out the cap onto the engine. Did you actually *pressure test* the radiator cap? Rather than the much higher cost of buying a radiator cap pressure tester, just buy a new cap, hose off the engine and radiator, and retest for the smell.

If you still smell the coolant, have the mechanic pressure test your whole cooling system. You could have a hose that is leaking. I hate those wire clamps which are just 2 wires holding down the hose. When one is found weak and causing a leak, I put a band clamp on it (as long as the metal tube's ridges, if any, are wide enough apart to let the band clamp fit between them). If there's a slow leak that burns off the coolant so you can't see the leak, a pressure test might expose the leak so which clamp or hose to replace becomes evident.

Reply to
VanguardLH

Did you check the overflow hose from the radiator cap to the overflow tank? The coolant expands when heated and some gets dumped into the tank and gets sucked back in when cooled. If the overflow hose is leaking then it could be the source of stink when you are driving the car. That hose may not be clamped but just pushed on and its elasticity creates a seal. Well, with a 14-year old car, rubber gets old and isn't as elastic anymore (and why I also suggested having a pressure test performed to check all the other hoses and even for a pin hole in the radiator at a solder joint).

Reply to
VanguardLH

Thanks for that valuable info. Pressure test booked for tomorrow and the current considered opinion is that the heater matrix is the culprit. Oh Joy! That ain't gonna be cheap if so. I'll let you know. Thanks again.

-C-

Reply to
fourstring

Problem solved! Thankfully it was not the heater matrix dying on me. Pressure tested and the culprit was found to be a very small leak from the bottom union rad top hose running down on the exhaust. A small amount of cooked antifreeze makes a very big smell. Many thanks for your interest and help.

Best

-C-

Reply to
fourstring

If it had been the interior heater core, besides the smell you wouldv'e noticed a film building up on the inside of the windows (but I don't know how long you've noticed the odor).

Hopefully the shop uses a band clamp, if applicable, instead of a 2-wire clamp when they replace the hose. Might be something you could repair yourself. Just get a length of hose and a clamp from the local car store.

So how much did the car shop charge for the pressure test and leak detect? Some car stores will rent you the pressure test kit for around $80 USD. Of course, then you would have to poke around looking for the coolant leak. They might add dye to the coolant that glows with ultraviolet light to make easier finding the leak.

Unless the engine gets hosed off or wiped of the leaked coolant after the leak repair, you'll want to set the air control to recirculate instead of fresh air until the coolant on the engine burns off.

Reply to
VanguardLH

My local garage is not a Subaru specialist (nearest one 40 miles) but they are first class mechanics so I let them sort it out. They pressure-tested for 3 hours to find the very small leak and cleaned and refitted the hose with a proper clamp for a very reasonable charge of £50...approx $70. A couple of hard runs has pretty much got rid of the smell... just hot engine fragrance...much better. Many thanks.

-C-

Reply to
fourstring

I had it twice with no signs of leakage on my '03 Forester. First time, dealer replaced the water pump and a year later when it returned I had the head gasket repaired.

Reply to
Frank

Not a bad idea to always use a single bottle of the Subaru Coolant Conditioner in the system. Install per directions (never pour it in the overflow tank) and, if the system is ever drained, put a bottle in with the new coolant.

No, it doesn't replace a proper repair - but it can reduce/cure slow external weeping of a headgasket and small leaks.

Reply to
1 Lucky Texan

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