Yesterday, I had to pull the intake manifold off of my girlfriend's '00 LS because it had a bad gasket from a previous direct port nitrous install and there was a vacuum leak. So I replaced that, and now I've got this coolant leak I can't seem to find. I checked all the coolant hoses and it's not coming from any of them.

It doesn't leak when the car is at idle, I let it idle for a half hour and nothing. But when I take it for a drive, for say 5 minutes and come back, it's leaking pretty bad.

It looks almost like the leak is coming from the intake manifold itself, but I can't be sure because I can't see up there well enough. As far as I can tell, it's coming from somewhere underneath the far left runner. That's where the coolant line goes into the manifold, but that line isn't leaking, there's no fluid there.

 

https://honda-tech.com/zerothread?id=665834

long shot.. but may help!!

 

Wow, that was pretty much the problem I was having. The IACV was throwing a code, so I fixed that along w/ the vacuum leak. Unfortunately, neither the IACV nor the TB have coolant lines anymore. They were rerouted to the turbo. So it's not that. It isn't the radiator either, we just put a new Fluidyne in last week and no leaks.

It looks like it's actually coming from the manifold. Is that possible? I can't be sure, but it looks like coolant is seeping out between the IM and head. All the bolts are torqued to spec. Are there any coolant passages on the IM other than the one near the passenger side?

Thanks for the help.

 

I have a very small leak coming from the bottom hose of the radiator. This only started to happen after I put on my Fluidyne, so maybe that's it.