now overheating

[cheapmj]

i have a 91 4.0 5sp i put a grill in now it start to over heat never had this problem before

it always ran at 210 deg.

[Jerry]

What sort of grill?

[cheapmj]

no a stock comanche grille over heats on highway but does not in city traffic

sorry for no e on grill on first post

[mvusse]

My Suburban has done it, My Geo has done it, and my Cherokee is doing it. All three due to a clogged up radiator. Allows enough coolant flow to dissipate the heat from city driving, but not enough to handle the heat generated from extended runs at 1800+ rpm. If it was an airflow issue it would overheat in city traffic, but not on highway.

[dasbulliwagen]

Had that happen recently on a customers car, they took it to a shop for a flush, the shop flushed it then installed a cooling system sealer stuff ( like stopleak) and then had overheating problems... radiator inside was completely gummed up, installed a new rad, and all was well.

[ParadiseMJ]

A grille is not going to make the thing over heat. You have other problems.3

 

MY rule of thumb, others may disagree.

Overheat on hiway at speed: Coolant flow problem. Either a bad waterpump or clogged radiator, heater core or engine coolant galleries. A flush n' fill COULD solve that, especially important is flushing the heater core independently of the rest of the system. Just a garden hose from the top and then alternate to the bottom until no more crap comes out (I have used CLR on the core with great results).

 

An old or worn radiator cap or air in the system are also prime suspects.

 

Overheat at idle, in traffic, under load or slow & go: Air flow problem. As said, the grille is not going to restrict air flow enough to make a difference. Either a bad fan clutch or a bad e-fan. Also check for crap, mud, bugs, leaves etc...and if you have any other accessories in front of the grille/radiator like a winch, a bank of lights etc that WOULD actually restrict air flow.

 

Sounds like a little work but well worth it!

[cheapmj]

thanks a bunch for the information i will work on those area