running hot!!!!!!

okay so i had a custom winch bumper installed on the xj and when i was driving home doing about 80 mph, it runs almost in the red. but when im at idle or around town it's fine. I was forced to run the heat into the cab to keep the engine from overheating. Now i have my little electric fan wired to run all the time. I did take off the little splash guard for the new bumper. I dont want to have to upgrade radiator b/c it's a bit pricey and the one there is only a few years old. Its an 88 4.0 , so.... should i upgrade to some kind of better fans (i hear the HO electrical fans are better) or should i try to go cheap fix first with Hood Vents (and what makes the la baron ones the most popular application) or do i buck up and get a 3 core radiator? It only runs really hot when im reving high on the highway, but the rpm's are nothing out of the ordinary b/c it is geared properly. Sorry for the long thread, just trying to get opinions

first try the newer model fan, more fins, and they move alot more air.
also, have you ever changed your fan clutch?

no on the fan clutch, it's original. I was gonna just do both the electrical fan and the hood vents and i cant see why it wouldnt at least help, if not solve the issue. hey how do i check to see if the fan clutch is shot?

If the fan clutch hasn't been replaced, at that age, I'd consider it bad. They are only like $30 or so, so it sure wouldn't hurt.

30 bucks you guys have it to easy, i just bought one here in Australia for 300 bucks, fitted it and hated the noise so its now dumped in a corner and i replaced it with an electric fan

LOWTECH said:

http://www.olypen.com/craigh/cooling.htm

Click to expand...

I REMEmber seeing this once b4, very interesting article, thank you for the link. Allright so here's my game plan, do the hood vents and the better electric auxillary fan first. See if it works. If so than im good, if not then i will definately do this cooling system conversion. Seems like something i should just do anyway because of the benefit of the 3 core radiator and the closed system. Everyone, thank you for input, if anyone thinks im going in the wrong direction than fell free to speak up.

-Mike

A new fan clutch wont hurt but the fact that it's idling without getting too hot tends to indicate that your fan is OK. Sounds to me like you have an airflow problem at highway speeds as this is the only time you're in the red. The obvious culprit is your new bumper. I'm assuming you only got this after you fitted it.

Do you have your winch installed and is it blocking the grille? What bumper do you have? Pics?

I have the same problem although not nearly as severe - My junk runs about 215 on the highway but will idle at 205 all day with temps outside of 110 plus.

Pull the bumper and see if you're still running hot.

Andre

i dont know how to host the pics, they r on my pc, but i also have a pic on my email i could forward you. Yeah it was fine b4, the bumper and so it's def an airflow issue. Thats why i was gonna start with hood vents and the HO fan

you probably already know this but when your XJ starts running hot there are a few things to check/replace before you to to anything expensive: T-stat (cheap and easy to replace should be done regularly anyway), check the radiator cap's ability to hold presure, if it is not holding pressure replace it, again, this is cheap and easy to do, next, check you water pump, typically they drip a little coolant to let you know that they are bad but not always. If all of those things are relatively new and/or in good shape then start looking at the fan clutch, and the radiator itself (bent fins, etc., have it flushed to make sure it isn't clogged, and flush your engine block while you're at it, etc.). Also (again common sense) make sure that all of your hoses are in good shape and are not leaking or bloating (over time the heat can wear down the rubber and make them less efficient at moving coolant around. Many of the things listed above can go bad even if they are relatively new so it is important to check them if you are overheating.

Aftermarket stuff can help with heating problems: flowmaster and other exhaust (cat backs and the like) can help move heat away from the engine and a fresh air intake located external to the engine compartment can also help keep the engine cooler.

good luck.

xjrugger said:

I REMEmber seeing this once b4, very interesting article, thank you for the link. Allright so here's my game plan, do the hood vents and the better electric auxillary fan first. See if it works. If so than im good, if not then i will definately do this cooling system conversion. Seems like something i should just do anyway because of the benefit of the 3 core radiator and the closed system. Everyone, thank you for input, if anyone thinks im going in the wrong direction than fell free to speak up.

-Mike

Click to expand...

Yea I had all sorts of problems too until I installed hood vent - presto no problems and I live in Tucson, AZ, 113 right now, (but it's a DRY HEAT).

If that's the original radiator, it's probably clogged by now. Last time I looked, Radiatorbarn.com had a decent 2-row for $110 (I think that included shipping) and the 3-row. You could go for a 92 model and convert to the less problematic open setup at the same time.

im performing all the checks this weekend, im thinking of doing hood vents regardless to keep it a little cooler anyway.