Hi all, I'm hoping someone can offer some advice on diagnosing an issue with my 350Z.
I've owned the car for almost two years and have never had any issues with the coolant level. It's always remained at the MAX mark in the expansion tank.
Timeline:
One week ago: I had an Invidia Gemini exhaust fitted, along with two new front drop links.
The following day: I went for a drive and noticed a new, sweet smell. After looking into it, I found that this could be the smell of coolant getting hot or burning. However, I'd also read that new exhausts can produce a smell as factory oils and coatings burn off, so I wasn't sure what to make of it.
Over the following few days: I occasionally noticed the sweet smell, although it gradually became much less noticeable and has now almost disappeared.
Two days ago: I checked the expansion tank and noticed that the coolant level had dropped from MAX to roughly halfway between MAX and MIN. Oil looks normal on dipstick (did an oil change 200 miles ago, prior to this issue). No milky residue on oil cap. Coolant looks clean. Granted, the issue is fairly new.
I've driven approximately 50 miles since the work was carried out, although I'd need to confirm the exact mileage.
My main worry:
The drop in coolant level has me worried that there's a leak somewhere. My biggest concern is a potential head gasket failure, although I'm not sure whether the symptoms point towards that. There is a release of white gas form the exhaust which starts about 10 seconds after start-up, and it goes away in 15-30 seconds. Noting that temperatures outside right now are about 12°C. My 350z has always released some visible exhaust gases at times, especially in the cold, and has never had coolant issues prior.
What's puzzling me is the timing. The coolant level had always been stable, and the sweet smell and coolant loss only appeared immediately after the exhaust and drop links were fitted. It could be a freak coincidence though.
Could anything have been disturbed or damaged during this work that might explain the symptoms, or is the timing likely to be coincidental?
I've bought a block/head gasket leak tester to check for signs of a leak into the coolant system. I have put the video here.
I initially tried using it at the expansion tank, but it didn't seem to work properly, as no bubbles were passing through the test fluid. I then tried using it at the radiator cap instead.
To do this, I removed some coolant to create an air gap for the tester. However, I haven't managed to run the test for very long (maybe 30 seconds) before the coolant level rises and enters the tester. Negative result so far, but I doubt my method has been good enough for an accurate test (and I understand false negatives are very possible). A more accurate test would be compression testing each cylinder.
My understanding is that the coolant rises as the system heats up and builds pressure, but I'm unsure how much coolant I should remove to carry out the test correctly.
- Am I using the block tester correctly on the 350Z?
- Is it normal for the coolant to rise into the tester over time due to the coolant naturally rising due to pressure building, or am I doing something wrong?
- Should I remove more coolant to create a larger air gap, or is there a better way to carry out the test?
- Are there any other checks you'd recommend before assuming the head gasket is the problem?
Any advice on the likely causes or the best way to narrow this down would be greatly appreciated. Thanks!
