1993 Rodeo Overheating

Great forum. I've been scanning over this the past hour or so and have a question.

I've seen this topic here a few times and wonderred if it applied to my situation. I can run forever on the freeway, but as soon as I come to an exit and slow down, the temperature guage jumps up until I rev it back up. The only water I seem to be losing is out of the top of the overflow when it gets really hot.

I have a new radiator (about 1 year old), changed the thermostat, cap and the fan clutch seems to be working. My mechanic can't even figure this out as he never took it on the freeway and wasn't able to get it to heat up. I was wonderring if the timing belt (or tensioner) could be the culprit. Is the water pump driven by the belt on this year?

Edit: BTW, its a 3.2L manual.

yup, water pump is belt driven. If you don't know the history of the pump then I would swap it out (along with the belt and the belt tensor too).

Thanks, I thought so. I have about 45k-50k on the current belt and tentioner so figure they are going to need replacing soon anyhow. I think the pump is original (about 270k).

wow! with 270k on the pump I would for sure swap it out.

Are you using OEM Isuzu thermostat - if not, get one in there asap! These truck's don't stay cool on anything else.

Haven't ever used an OEM therm., but have read all their praises on this site so I guess I should. Thanks!

So I take the freeway home (40 miles) today without incident and about 2-3 miles from my mechanic, I run into traffic. I wanted my car hot but not overheated (and damaged) to show him, so I throw on the heater. The heater blew cold until I reved it a couple times and then blew hot and I was unable to get the darn thing to heat up....so I went off to happy hour. On the way home, sure enough...there goes the guage. I hit the heater again and sure enough, it blew cold until I reved it. As the blowing air warmed, the guage dropped. I think it it pretty darn safe to say it is water pump/timing belt related now!! Thank you all for providing and poarticipating in this site as a refence point and a bit of sanity saver.

I bought the car brand new (42 miles on her) and am not ready to give up just yet.

(I now know how to present it to my mechanic, will bring it to him tomorrow and will post back with the results soon.)

i'd like to know if you got any fins left on your water pump? possible from electrolosis? 270,000 on a 3.2 water pump has to be a record? mike

You could be low on coolant and getting air pockets. Mine has done this before. I've been only a couple quarts low and had this happen.

I'll second it not requiring much air to overheat. Before my trip north I changed my coolant and filled only once. I didn't recheck the level and got hot on the ride back. I'm guessing I had some pockets there. I only added about a half or three-quarters of a quart of coolant to the top of the rad and the level has been good since.

Well, after dumbfounding my mechanic, the job is done. He didn't believe me that it was the tensioner or timing belt until I explained the logic behind it. Thanks for the input Cat and Surfer, but the cold air through the vents with the heater on was the giveaway and what made him (my mechanic) do go for it like I asked. Turns out the tensioner was the main culprit and not holding. The water pump was ok, not great as was the timing belt (I guess I had it replaced a couple timing belts ago...he looked it up in his records). For all of that labor I had them replaced as well as all of the other belts (and the tensioner of course), this way I only got charged labor for a water pump replacement, plus parts. All told, only $480.00. My guy only charges labor plus his cost on parts (plus he never charges for petty stuff like coolant). Plus I had the gal back within 24 hours. How do y'all think I did on the bill?

Thank you all so much for helping me put this problem to rest and to be able to stop worrying about screwing up my engine. WOOT!!

Only $480?? Not bad! Got it back in 24 hours - even better!! Tom

Holy schmokes!

You replaced all belts, tb, tb tensioner and waterpump (??) for less then $500?? Can't figure from your post if the waterpump was replaced.

Either way, I need to find YOUR mechanic - I was robbed cold in comparison!

Yep, including the water pump. My mechanic is in Burbank, CA. If anyone wants his number, let me know. (BTW, he's even open on Saturdays.)

might as well give him a free plug here for future searchers...

//bc