Coolant smell

[Dconger74]

Just bought a new to me 2004 silverado with a 5.3L. Smelling coolant when I get out of the truck after it's up to temperature. I don't smell it inside the truck nor do I have windows steaming up on the inside. Just the smell outside. I see no evidence of a leak. The water pump was changed on this truck right before I bought it.

 

Now I have been reading all over the internet on various websites about a casting defect in the cylinder heads. These being the dreaded castech heads. There are reports of losing coolant and no evidence of where it is going. My question is if you do have these heads and are losing coolant do you smell it when up to temperature if it's internal? I think you would in the exhaust I just curious if you that have had this trouble smelled it in the engine Bay Area. Thanks.

[Gurrzt]

When engine is cold, take off radiator cap, start the engine, when engine warms up, if you see "bubbles" rising to the top, you have a problem with the heads, however a cracked head would be indicative of the engine overheating.

[PJB1972]

With the water pump just being replaced, is it possible that there are some coolant puddles under the hood somewhere?

[Dconger74]

The truck has 91,775 miles on it and from what I have read the head problems occur around this point. I have drove the truck about 300 miles since buying it. And quite frankly I never dreamed of these trucks have this kind of problem. If I had known I would've stuck with my intentions of buying a toyota. But after driving this many miles I would've thought that any residual puddles would've dried up by now. It's not as bad as when I first noticed it but there is still just a hint of it. Also if the heads are the case, will you have any of the sludge under the oil cap? Mine is dry as powder. Good sign.

[PJB1972]

Coolant in the oil will create a butterscotch looking goo in the engine, including under the filler cap.

Additionally, I think if the coolant was leaking inside the engine, you wouldn't smell it.

[The Zip]

Since you don't see a leak, whatever is coming out is dissipating on your hot engine. Check your hose running to the water pump for cracks which may allow a small amount of coolant to run and dry on the block. But what may be easier is to drain some coolant from your overflow reservoir, when the engine gets up to temps, it maybe overflowing. But that may be an effect to another cause, is your engine running hot and why. Hope it's just too much coolant or faulty hose

[Dconger74]

Temps after warm up are just below to 210 mark on the gauge. The smell is not nearly as bad as when I initially noticed it. It's just faint now. You will catch a whiff of it and then you can walk around checking and never really smell it again and other times you can. My main concern or question is if it were the heads, since it is all buttoned up (internal), would you smell it in the engine bay?

[PJB1972]

My castech heads failed at 220,000 miles.

I never smelled a thing.

[takethebounce]

Pull off the top of the fan shroud so you can see the back of the rad and start the truck. Could just be a pin hole in the rad and sprays on the fan blowing it around and not leaving any trace of a leak but will smell like a larger leak with it blowing everywhere.

 

 

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[Dconger74]

If it ever stops raining around here I'm going to give that a go. I've tried looking under the truck with a light but can't really see much. I'm thinking it's a small leak in a hose or like you said the radiator. I made a mark on the overflow where the coolant level was. Gonna give it a week or two and see if it drops very much.

[durandetto]

There's a good chance it's the water pump gaskets. Very common and you'll almost never see a leak on the ground, because it burns off on the block.