JRubycon08

HELP! Engine squeal on my 2008 JKU with 247K miles. Also, getting cold out and noticed heater doesn’t work like it used to (cooler on driver’s side). Any advice on repair is appreciated...

Replaced 5/11/21: Alternator, Drive Belt, Idler Pulley, Tensioner
Replaced 8/4/21: Belt Tensioner
Replaced 9/28/21: Starter, Spark Plugs, Wires, Air Filter

Replaced at 185K: Lifters, Timing Chain, Spark Plugs, Bolts/Gaskets, Water Pump, Radiator.

Mark Doiron

Pick up one of these and start poking around ...

https://www.napaonline.com/en/p/BK_7...&gclsrc=aw.ds&

cartoscro

I'm not much help on the squealling, but the heat issue is likely your heater core clogged. Very easy fix if you use the method in this video. Otherwise, the whole dash has to come out.

resharp001

Can you expand on the engine squeal? What does it sound like? When does it happen? Is it constant or intermittent? Does it happen at idle or only at speed?

I'm a little confused if you're just throwing all general maintenance in this list or if you're implying this could be an internal engine sound given some of the items listed here.

Agree, the heater issue is likely a clogged heater core.

Mark Doiron

Which brings up the question, what coolant have you been using? The wrong stuff can create particulates that lead to lots of trouble.

JRubycon08

It squeals all the time and during acceleration. Then over 50 mph it seems to quiet down.

Yes, throwing out general maintenance, because I’ve tried to care of her. She’s pushing 250K...