Losing Coolant

[collins_dan]

I have been noticing a slightly sweet coolant smell when idling and am needing to add about a cup of coolant per tank of gas. Nothing dramatic. Running great, particularly at speed. Getting hotter than I would like sitting in traffic, but again nothing dramatic. No oil in coolant or coolant in oil. No bubbles into overflow bottle at idle when at temperature. Assuming a head gasket leak into a cylinder and getting burned up. Anything else to check before pulling off head? Thanks, Dan

[ardee_selby]

Eliminate rad cap seal, per this discussion, first?

Ref: elan-f14/cooling-the-elan-europa-t23368.html

Cheers - Richard

[m750rider]

Dan

From your description it sounds more like a small leak and not a head gasket. Check the coolant hoses and radiator. Have you checked the weep hole on the water pump? Have you checked the heater core - if you can smell coolant it might be there. A small leak might evaporate before it created a leak that showed on the ground.

Bob

69 S4 SE

[simonknee]

I'd check just about everything before pulling the head.
If you can smell it it is pretty much NOT getting into a cylinder.

Simon

[simonknee]

Check the core plugs and the drain tap on the block.

[RotoFlexible]

+1 on checking hoses. As part of my major overhaul, I got new hoses and authentic-looking wire hose clamps. I tightened everything, and they leaked. (Took me a while to spot it.) I tightened some more, but eventually they leaked again. In most locations, I've gone back to band (jubilee) clamps.

You feel like an idiot when it turns out to be something as simple as a loose hose clamp, but also very relieved that it's not something more.

[nebogipfel]

If you can smell it it is pretty much NOT getting into a cylinder.
Simon

I agree with Simon.

The sweet smell would suggest heater hoses or matrix to me.

[JJDraper]

Ditto head gasket as last resort.. I understand some coolant additives fluoresce under UV light, aiding leak detection. Might be worth getting hold of hand held UV light (banknote checker?) and looking around the engine bay (in dim light). I had a similar coolant loss problem, with the gasket failure at the rear of the head. Head needed an overhaul anyway.

elan-f15/rats-losing-coolant-t24742.html

Jeremy

[prezoom]

Generally, if you can smell coolant, it is hitting something hot. Take a look around the exhaust side of the engine.

Rob Walker
26-4889

[rgh0]

check the drain hole from the pump - a small leak can hit the pulley and belt and get thrown around the engine bay as a fine mist - easy to smell but hard to see and it can stop when the engine stops also so nothing to see when you check for leaks

cheers
Rohan

[collins_dan]

Thanks for all the tips. Check the heater box and connections. Too dusty to be in there. I checked all the connections and I wiped the engine down all over. Looked a little wet in the right rear corner, so I am suspicious it could be back there. Drove it once since and no signs anywhere. Rohan, when you had your slight head gasket leak that you didn't discover until removing the head for other reasons, where was it?

Thanks. Dan

PS. Should mention that radiator cap checks out. Good flow between radiator to overflow bottle and back. I went back and looked at Jeremy's pictures of his leak at the back of block. This is where I am suspicious, as it looked wet, but after wiping couldn't see or smell coolant. My gasket protrudes at least 1MM back here. I wonder if it was put on correctly last time? There is a very clear line of copper along the back edge. The engine was rebuilt in 2007 and head re-torqued last summer, and I don't recall it being out of spec at that time.

[rgh0]

The failure i had was a fatigue crack in the gasket fire ring in one cylinder. This was enough to let a very small amount of combustion gas to leak into the coolant with the crack closing up again when no combustion pressure so no water leaked back into the cylinder. The gas and some water would also come out into the over flow bottle and thus when the engine cooled down most of the water was sucked back into the engine / radiator from the overflow bottle.

The egine ran hot but never lost a signficant amount of coolant and It was only when finally found bubbles in the overflow bottle after a short sprint track day that i finally pulled the head and found the gasket fire ring crack as the cause.

cheers
Rohan

[collins_dan]

Thanks. No bubbles in the overflow bottle, so I don't think that is it. It would appear that a couple more cups of coolant are in the overflow bottle when the engine is hot, which returns into the engine when it cools down. I assume that is just due to expansion. Thanks, Dan

[JJDraper]

Dan, if you could see something wet, try tasting the liquid - just a tip of a finger. Sweetness = coolant... as long as you have some glycol based antifreeze in the system! It is poisonous, but not in tip-of-finger quantities.

Jeremy

[collins_dan]

I have found the leak. The pictures are not great. If you look at the bottom of the flashlight on the first picture, you can see a small puddle of green on the block. The second picture shows much more clearly two puddles of green on the block. It is as I suspected leaking along the back of the head. Should I pull the cam cover and try re-torquing the head? I've never done this before. I've searched the archives and it sounds like no loosening, just tightening. I'll consult the shop manual to get the torque setting and sequence correct. Any tips appreciated. Thanks, Dan
PS. Jeremy, I used a halogen flashlight this time and the color was very obviously green.