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I've noticed a small leak coming from the cap earlier this week. Mentioned it to my tech and told me not to worry about it (!!!). After a spirited ride today (sometimes near red line), I noticed smoke and coolant behind the rear left-wheel. Lo and behold, the damn cap seemed to have failed big time!
I tried to tight up the cap but it seems like it's stripped or something.
The tank was replaced 2 years ago and it doesn't seem to be leaking from somewhere else. Luckily I already ordered a .04 cap to replace that non-OEM one.
I drove back home very safely and I don't see any leaks but can definitely hear air hissing from the cap.
Anything else I should look for? Too much pressure in the tank?
Those caps will leak over time. I never saw so much leakage as yours, but they do leak. Standard maintenance is to examine the cap for whitish, crusty residue around it... if so, then replace the cap. Same for that black cap behind it. I would replace with OEM since it is so cheap.
Your fluid looks dark cherry. How many miles/time on that fluid? As I understand it, as coolant ages and the additives are used up, the fluid darkens. Maybe consider a fluid flush? IMO, the fluid should be replaced at 100K minimum... but that is just me.
Those caps will leak over time. I never saw so much leakage as yours, but they do leak. Standard maintenance is to examine the cap for whitish, crusty residue around it... if so, then replace the cap. Same for that black cap behind it. I would replace with OEM since it is so cheap.
Your fluid looks dark cherry. How many miles/time on that fluid? As I understand it, as coolant ages and the additives are used up, the fluid darkens. Maybe consider a fluid flush? IMO, the fluid should be replaced at 100K minimum... but that is just me.
The fluid was flushed last year. It's more pink than in the photo. However, I'm staring to wonder if I didn't cause the leak. I removed the cap yesterday to clean the previous leak in order to monitor things and I tightened the cap as much as I could. Perhaps it wasn't enough and somehow it got loose? I don't want to damage the tank so I'm not trying to tight the cap too much for now as it seems stripped. The car won't be out until next spring anyway so I'll wait for that new .04 cap and hope it was my mistake and/or a faulty cap and now the 2-year old tank that gone bad.
There isn't an overflow tube, the cap just vents out the bottom of the cap.
Cap feeling stripped is weird, you should be able to tighten it up snugly. Pull it off and see if you can tell what's going on. I'm betting the cap itself has broken, probably if you just replace it you'll be fine.
The OEM coolant caps are blue in color, not black, so perhaps you have an aftermarket one. I’d buy a factory coolant tank cap and see if that corrects the issue.
The OEM coolant caps are blue in color, not black, so perhaps you have an aftermarket one. I’d buy a factory coolant tank cap and see if that corrects the issue.
The OEM coolant caps are blue in color, not black, so perhaps you have an aftermarket one. I’d buy a factory coolant tank cap and see if that corrects the issue.
you will just shift the weakest link to another spot.
possibly but in this case I doubt it… the two caps are pretty good designs, just go with oem parts. With a new aluminum part you can change the shape of the part and never have to worry about it cracking due to age/heat cycles
11-04-2022 | 11:23 AM
Major expansion tank cap failure?
Already ordered a .04 cap.
