need some help

[cateraowner]

got a couple questions. gonna head back to my dad's house on saturday and will get my car on the jack to pull the air compressor and change the spark plugs. I was thinking since I'm doing that I want to find out where the coolant is leaking from. there is no sign of any leak what so ever, but I end up losing about 1/2 liter every 2 months. and when it's warm and I drive my car pretty hard I can smell the coolant.

before I do that I need to know a couple things.

I took a picture so it'd be easier for me to explain.

first question is for #1 on the picture.
-the hose going from the coolant tank to Throttle body.
what does it do? does carry? it seems to high in the tank to be coolant unles it going to the tank.

and #2 I noticed there is a splotch there, not sure if it's oil or coolant. does coolant or oil go throuhg thatset of tubes


what I was hoping is if since the cooling system is under high pressure I have a loose hose some where and the coolant is vaporizin or something.

sorry if I'm not being too clear but for now that's how I can explain it.

thanks for looking

[Po Pimp]

Yes coolant does run through the throttle body. Why? It is really only an advantage in extremely cold climates. Any build up on the throttle body bores can cause the butterflies to stick. It also slightly heats the incoming air in these enviroments to attempt to gain some fuel economy, although, not very much. This is only in extremely cold weather. With a longer length hose of the same diameter and an adaptor piece you can connect both coolant tubes together. On different engines it can yeild up to a 10 HP gain. Not sure how much how much you see on a Catera but I have already did it to mine with no ill effects. If it stays below zero in your area for a chunk of the year you might not want to do it.

I suppose you could be losing coolant from there but I think a more evident trail would be left. You have to consider wind and the fact that the front of the engine is not that hot. You would probably see some white staining of the plastic and surrounding metal assuming that is has been going on for a little while.

These Cateras like to leak coolant out of the backside of the engine. Which is rather hard to see. I would suggest that you take off the windshield wipers and the black (scuttle pad) plastic piece underneath them. Not hard to do just remember that there are connects hidden from view beneath the rubber trim of the windshield. The HCV (or HBV) like to leak. You can find this directly behind the passanger side cam cover (valve cover). It has three coolant hoses and a vacuum hose, just in case you have not seen it before. Inspect this for wetness. It sit directly over the exhaust so if it is leaking slightly odds of you seeing anything on the ground are unlikely until it starts to leak bad. Also inspect the rest of the backside of the engine. Note any where you find wetness.

Since you are already changing the spark plugs inspect them closely for signs of oil. I see a big wet spot on the passanger side cam cover. That could very well be oil leaking past one of the bolts that secure the covers down. That could also be what you are seeing in terms of wetness on the front part of the engine.