Overheating - garage issues?
 

My MY96 STI import is currently in the garage, the temp needle keeps wandering up to 3/4 and the back down to 1/2. The heater has also been playing up going hot and cold opposite to the temp of the engine!

Well, the garage phoned me this morning to say that the Radiator and thermostat were shot....they've replaced them, taken the car out for a drive and after 10 mins its doing the same as before!!

Can I tell them to put the old radiator back on? Can they charge me for something that doesn't actually fix the problem I asked them to fix???

Please help as I need to go back to the garage this afternoon.

sounds like could be air lock !!!

Think you can ask them to put original items back on
Im afraid they will still charge you for the investigation/man hours spent looking at the problem

The garage just phoned to tell me they've by passed the heater matrix and its still overheating....this in turn cracked the header tank so they want me to buy a new one!!! They say the pressure is too high in the cooling system!! Any ideas?

Mods - please move to technical section if you wish?

Headgasket gone?

No sign of mayo in the oil, etc so hopefully not? They checking now!

Mayo only means the head gasket has gone between the oil and water.

Could have gone between a cylinder and water. Only has to be small and it can suck water out into the cylinder which is then burnt off. Or it can push combustion gases into the water system. Or both!

Had it before back in the days of being a vehicle technician for a main dealer!

Have they done a compression test and a cylinder leakage test. The latter often finds the effected cylinder - an adaptor is fitted inplace of the spark plug and compressed air forced into the cylinder (have to rotate the engine so that each cylinder has both valves closed for the test).

Or a quick test is run the engine in the workshop with the rad cap / erxpansion cap removed, if its bubbling up and over flowing then its a sign!

I've not been losing coolant though, wouldn't coolant levels drop if the gasket had gone??

Sorry if stupid questions, just trying to get my head around how it all works?

Not always.

Any coolant lost is replaced by air locks in the system so the levels can appear the same.


This is assuming the garage is correct when they say "too much pressure" in the water system.
They might have blown the gasket themselves.

Sorry, but I'm glad its not my car!

I decided to take some legal advice before returning to the garage so could be fun later!! I've been told if the head gasket has gone then I shouldn't be paying for the radiator as it was not the cause of the problems and the garage should make good the damage to the header tank (ie replace free of charge).

Then start crying and work out whether to strip the car or get the gaskets changed! :cry:

Cheer up . . . It might not be the head gasket!

get the garage to do a sniffer test on the coolent if the chemicals in the sniffer change coulor the head gasket is foobar if they dont have one take it to one that does most wont charge for this service and the ones that do only charge less than a tenner worth it and will help you make your mind up as wether to fix it or brake it

hope this helps dave

cracked head also cause pressurised cooling system , hairline crack allowing pressurised gasses into coolant on compression stroke, but closing on induction so no steam or mayo, but as mentioned, can still be gasket. easy way to check is to start from cold, and feel coolant hose, does it pressurise, if so, then head or head gasket prob/. tbh, the garage should have checked the basics first, and perhaps your car would be better off in the hands of someone else.

The car passed the sniffer test so they now think its the water pump?
Does that sound right? The water pump was replaced in March 2008 so if its failed at least its covered under warranty!!

They said the cooling system is pressurising very quickley after start up.

I will put money on its either head gasket or needs bleeding properly.

The water pump "pumps" water around the engine.
I doubt that has gone.

The key here is that they say the cooling system is presurising very quickly!

Based on that, my money is on it being a head gasket or cracked head!

From a cold engine, with coolant filled up, remove the expansionbottle cap.
Start the car and observe the coolant in the expansion tank ove the next ten minutes.

If bubbles start to appear in the coolant and/or the level starts to rise and/or the coolant overflows then its a sign the coolant system is being pressurised from the engine.
Cracked head, cracked block, head gasket - thats what you are looking at.

Faulty radiators, thermostats, water pumps are easy enough to diagnose for a competent mechanic. Even thoug I've been out of the trade >15 years I could still diagnose them.

Hope you have some luck and it turns out to be something not so expensive.

And DON'T pay for the garages inability to correctly diagnose faults.
1 hours labour is the most you should have to pay.

Did you sign anything giving themm authority to changes any parts they wanted to?

Thanks for your reply.

I'm just letting them get on with it at the moment and arguing over the bill at the end. I haven't signed anything to give them authority to change parts.

They're supposed to be one of the best garages around my way so I'm really shocked all this has happened.