Engine overheating

[Matthew Mushongo]

I have a Isuzu pick, with a 3.60 liter engine capacity. It’s an automatic transmission. I bought this car 3 years ago and had no other issues except engine poor performance during traffic congestion. The car hesitates to accelerate after being in traffic congestion for more than 5 minutes. I took the car to a mechanic and he tested it by hooking it to a diagnostic tool. The error codes indicated that the gas pedal is faulty. I replaced the gas pedal but the problem still persist. The oil pressure sensor was replaced and new software for the ECM was loaded. Things looked fine for a few weeks and the problem still didn’t go. After watching the video on torque converter and automatic transmission by Eric, I found the intercooler leaking . Once again, I had the intercooler repaired and pressure of the cooling system checked.

The engine only hesitates to accelerate after the check engine light and service light appears on the dash board. When this happens, i usually pull-over and switch of the engine. After few restarts and sometimes forcing the car to accelerates, the engine start to perform normal again.

The other problem is that the engine gets hot every time I drive the car for more than 10 km. The situation gets work if the aircon is switched on. mechanic at the same workshop told me that the head gasket should be replaced and the wiring harness of the entire electrical system should be replaced. The total cost is about. $ 2100. I am scared that disassembling the entire engine block to replace the head gasket and wiring system will not only cost a lot , but might lead to some serious trouble if human errors during the entire repair process occurs.

Topic

[college man]

Before anything else. lets diagnose the overheating.
Has the thermostat been changed? coolant changed?
more in this link.

http://www.ericthecarguy.com/faq/what-to-do-when-your-engine-overheats

[Matthew Mushongo]

The thermostat has not been changed, neither the coolant.

[Dr. Jerryrigger]

Does the radiator fan come on? Is it more likely to overheat at higher or lower speeds?
Knowing the little I do I’d guess you have a thermostat that is stuck closed. You can test this by removing the thermostat entirely and driving without it. If the problem goes away buy a new one, if not keep looking for the problem.

[Matthew Mushongo]

The engine overheats irrespective of the speed I am driving. What I have observed is that it overheats more when driving uphill, when accelerating by pressing the gas pedal and when the cooling aircon is switched on. I tested the radiator fan by turning the aircon on full blast. The behind the radiator turned on. The only thing I didn’t do is to check the the thermostat, which I think I should test as soon as possible.

The temperature gauge usually returns to normal when the aircon is turned on to HOT instead of cooling.

[Matthew Mushongo]

Does the poor engine performance or lack of acceleration (when the maintenance and check engine lights comes on)also connected to engine overheating?

[Stephen Bowen]

A few things come to mind judging by some of your responses so far.

From a maintenance point of view–everything I’m about to suggest should be done every few years depending on driving habits and such.

Basics first: Thermostat. Don’t bother to check it, just replace it. It’s a cheap part. By the time you remove it and test it? It’s just as easy to swap it out.

Hoses, both upper and lower. Check for squishy bits and anything that just looks weird. I mention this because we had a Ford Taurus come into the shop once, and the inner rubber came apart in the hose and created a nice fluid dam. Once the thermostat did open? The coolant flow filled the tear in the inside of the hose, and choked off the coolant.

Again, hoses and belts are every few years for replacement for general maintenance.

It also sounds like your radiator could stand to be flushed out. Normally when I hear that the fans are working—but the engine still runs hot or overheats–but cranking the heat on full makes it run colder? Sure—your heater core is working great as a ‘radiator’— But if your big radiator in the front is plugging up with crusty crud? That’s a tell tale symptom. Not saying 100% that is the issue… But I would look into it.

What I would do if the car was mine:

Drain the coolant and examine it: Fresh looking—or really yucky
Replace the Thermostat: Cheap part and good for piece of mind.
With the radiator drained out, and the hoses removed–
Stick a garden hose into the inlet and turn it on. It should free-flow at a good clip. If you see crud coming out? Keep the flow going until it runs clear. You can also do it backwards, but I would recommend hooking a hose to divert the water flow so you control the mess.

(hint: You can-depending on the radiator design- look at the internal parts with a flash light. If you see a great deal of crustys hanging off the internal parts? Fair chance the radiator is plugged.)

For more information, pick up a Haynes or Chiltons guide to your truck. It’s a life saver. (or whatever your auto parts house can order in for you)

As for the garage wanting to replace the head gasket and the wiring harness? That sounds like an bit much at this stage. As others have said: Let’s get the engine’s cooling on track. Unless they did a “Block Test” to detect exhaust/combustion gasses in the cooling system? I’d stick with the basic maintenance first.

S-

[Matthew Mushongo]

Thanks a lot for this valuable information. I will replace the thermostat and drain the coolant to see if it is contaminated.

[Stephen Bowen]

Please let us know how things work out. Also Eric has A LOT of great information regarding engine overheating issues. While his videos may not be for ‘your car’ directly? The principles are all the same across the board for system operations and how to figure things out.

S-

[Matthew Mushongo]

I just want to share with you one problem my friend’s had. His car is a Volkswagen Polo, Classic (I guess 2004 model) and started to have starting up issues and later on the engine could switch off itself while the car is in motion. One day while the mechanic was busy drive testing, the engine switched off itself. The car couldn’t start at all. The starter was diagnostic and replaced, but the car still couldn’t start.

An experienced mechanic came to test with his diagnostic tool to check the error codes, but couldn’t fix the problem. Fuses and certain sensors were replaced, but the problem couldn’t be solved. My friend was advised to dump the car as there was no hope that the car will ever start. Expensive repair were also suggested, such as engine overhaul.

One guy came and decided to take the challenge, and guess what? The problem was an electrical connection to the engine that was loose and was creating a short circuit. The wire pair were properly put together and the connection repaired. The car suddenly started an d the repair was such a cheap one.

[Stephen Bowen]

Always true. Never overlook the simple and stupid things. In the end? I’ve spent far to much time chasing my tail end, when suddenly the wife will walk up and say “What does this do?” (And it’s normally something like a wire plug I missed)

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[EricTheCarGuy]

As many have suggested, it’s probably best to attack the overheating issue first. Replacing the thermostat is not my first recommendation. In fact, I think you should do other testing first before replacing that part. I cover that testing here.

http://www.ericthecarguy.com/faq/what-to-do-when-your-engine-overheats

As it states you want to check for air in the cooling system and to see if it can hold pressure first. Also, there is a video in there that shows how to check for a head gasket failure which is what I would check for if the above tests don’t yield any results.

It would also be nice if you could post the codes the CEL is leaving for you. They will be an important clue as to that the issue may be.

Good luck and keep us posted.

[Author]

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