Where is my coolant leaking from?

[DoinkMobb]

Or should I say, from where is my coolant leaking?

I've noticed that my coolant reservoir always seems low. This weekend I noticed a puddle in my driveway under my Q. AC condensation, oil, coolant? No, it's coolant and it's dripping down the front of my oil pan.

I traced the coolant hoses as best I could and felt around under the plenum. From where I could fit my hand, I couldn't feel any wetness anywhere. What the hell should I be looking for? Is it time to remove the plenum and spend a week replacing hoses and whatnot? I am off for 9 days starting on the 22nd, so I could order all the necessary parts and crack the bastard open.

I've kept an eye on the temp gauge and I haven't noticed any fluctuations. I'd like to NOT have my engine blow.

[goody90q45]

With a flashlight you'll be able to look around under the plenum and easily see coolant pooled up in a number of places. If there's none there you're quite lucky.

If you're dripping down the front of the oil pan I'd also be checking the water pump (bleed hole?), thermostat housing and hose connections. I'm not sure about the pump since I haven't had to change mine but the thermostat housing has no gasket, only RTV sealant. Good luck.

[DoinkMobb]

I don't remember seeing anything blatantly obvious like a puddle under the plenum. I'll check again tomorrow in the daylight though.

I'm wondering if I should just remove the plenum and do everything possible under there while I have the time. The valve cover gaskets are leaking, the knock sensors are 174K miles old, there's a coolant leak somewhere, the sparkplugs could probably use a change, the TB needs to be cleaned, and I have an alternator I need to install. Awesome.

[maxnix]

Can you say under plenum job?

Your efforts to not dangle a partciple are commendable.

[DoinkMobb]

Can you say under plenum job?

Your efforts to not dangle a partciple are commendable.

Checking out under the plenum with a flashlight, I don't see any puddles of coolant. Actually, tonight I don't see any coolant dripping down the front of the oil pan either. What I see is a frayed hose towards the 3 o'clock position on the plenum right near the throttle cable. The hose faces down and then kinks 90 degrees under the plenum on the backside.

So will the hoses I receive in the under plenum hose kit from Joe most likely fix the leak? Coolant will serve me much better by NOT being in a puddle under my car.

I prefer my participles to be thoroughly kept in check. Ain't nothing wrong with writin' good.

P.S. Is there a NICOclub discount on infinitipartsusa?

[Q45denver]

Another thing you might check is the radiator cap as they can leak after a few years. I know on my 1990, I also had to replace the filler neck with a redesigned one as it kept leaking.

No real NICO discount but you can get 25% off by talking to Joe or ordering over the internet and sometimes they have specials. I think they sell a hose kit as well as a plenum kit? Better to Get-R-done before summer.

Checking out under the plenum with a flashlight, I don't see any puddles of coolant. Actually, tonight I don't see any coolant dripping down the front of the oil pan either. What I see is a frayed hose towards the 3 o'clock position on the plenum right near the throttle cable. The hose faces down and then kinks 90 degrees under the plenum on the backside.

So will the hoses I receive in the under plenum hose kit from Joe most likely fix the leak? Coolant will serve me much better by NOT being in a puddle under my car.

I prefer my participles to be thoroughly kept in check. Ain't nothing wrong with writin' good.

P.S. Is there a NICOclub discount on infinitipartsusa?

[maxnix]

Better to Get-R-done before summer.

Hell, do it now. Catastrophic coolant failures are fatal to the VH45DE and the heat gauge will let you know about 3 minutes after your engine is cooked. Just not worth fooling with it.

[DoinkMobb]

Another thing you might check is the radiator cap as they can leak after a few years. I know on my 1990, I also had to replace the filler neck with a redesigned one as it kept leaking.

No real NICO discount but you can get 25% off by talking to Joe or ordering over the internet and sometimes they have specials. I think they sell a hose kit as well as a plenum kit? Better to Get-R-done before summer.

I'm pretty sure the filler neck was replaced on my Q by the previous owner. I'm looking to take care of this problem this week coming up.

I e-mailed Joe and he gave me a price quote for the UPHK, knock sensors, KS harness and valve cover gaskets. I guess I'll e-mail him back and tell him I'm ready to order.

[Q451990]

I'm pretty sure the filler neck was replaced on my Q by the previous owner.

The updated design is cast aluminum... the old one is a flimsy brass. Good to know, because you only need a replacement cap if the neck has been replaced already.

Heath

EDIT: I think the design change I'm talking about was just in the early run... maybe 90 and 91 models? You should be fine just replacing the cap.