Car Broke Down, Suspect Headgasket

[chrisb1357]

Hi all,

Sorry this is a long post

The other day our Peugeot 306 1.4 8v 1998 decided to breakdown when the wife was driving home from work. When she was driving along all of a sudden the rev's of the engine went sky high and stayed high and the temp gauge started to rise so she pulled over and she also noticed some steam from the engine bay. She decided not to carry on and phoned the breakdown service who then came out in 20min. He took the cap of the radiator and said its a suspect headgasket and did not know why the engine rev's was nearly on the red line so she was relayed home. When they got home the car started fine and was not overheating and I have drove it around for last 3 days.

So my main worry is now why did the car rev high and stay high. A few weeks back I noticed the car stalling when pulling up to junctions so I suspected the ICV which I removed and cleaned with carb cleaner and it was very dirty and looked like the original part. After this It seem ok until the above happened. Could It be that the ICV is starting to fail and that's why it caused the rev's to stay high which in turn nearly overheated the engine.

With regards to the head gasket the guy who relayed the car back all he did was look in the rad cap. I have checked rad cap myself and no mayo in there and no mayo on the oil cap or dipstick. No smoke from the car and coolant and oil levels are correct and the engine temp seems fine. The only thing I can see on the top of the coolant is a very very slight film of clear oil. Its not black and the coolant is still blue.

So has the head gasket gone and does the ICV need to be replaced as I have done over 100 miles in last few days and its fine

Been quoted £460 for head gasket but that was without anyone looking or checking to see if it has gone or not.

What would people suggest.

Chris

[Peter.N.]

If the engine was running flat out for any length of time it could just have boiled, did it stop when you turned the ignition off?

Peter

[chrisb1357]

Hi

Well turned the engine off and started it a few hours later it was fine

Chris

[Peter.N.]

One of the reasons for an engine 'running away' is oil from the engine being drawn into the air intake but if it stops when you turn the ignition off it won't be that. Hang on a minute I'm talking rubbish yours is petrol isn't it, I haven't run one for about 30 years so don't know much about them now, but if it runs OK and isn't blowing the coolant out I would say you have got away with it, why it ran away I don't know but I expect someone who does will be along shortly.

Peter

[Stickyfinger]

If it boiled, it would be easy and cheap to get tested BEFORE you drive it anymore. Like all things, catch it early and you can save stress and a LOT of money

[chrisb1357]

Hi

Plan on getting it checked next weekend. What should I ask the garrage to do or check and what sort of price should the diagnostics and check cost me.

Chris

[Stickyfinger]

Hi Chris

1st, engine compression test incld a "leak" test.
Cooling system pressure test (best done as a vacuum test) and always AFTER the compression test.

Cannot think what would let it "run away" like it did ....which makes a Lexia session even more important.

[spider]

The only thing i can think of for a runaway (at say more than 2000 rpm) on a petrol is a snagged throttle cable. Although there may be an idle stepper motor even fully jammed open it can only influence running speed up to a point not all the way up the rev range, I'd expect it to not go to more than say 1500 with that jammed open.

I thought about electronic throttles but this 306 does not have one as far as I know so its likely a frayed cable possibly intermittent. Would only take a strand or two to cause it.

[chrisb1357]

Hi all,

Just an update on my problem.

This morning drove car 3 miles then got back in the car and started the engine. As soon as I started it the engine just rev right up and would only go back down if I drove along. When at juctions it would rev up again as soon as I stopped and also the rev counter only works when it wants to.

[addo]

Sounds like an air leak.

[chrisb1357]

Hi

People have suggest it could be throttle postion sensor

[citronut]

dose this car have an idle stepper motor,

although this us not the usual symptoms of sticking stepper motor, i dont see any reason it cant cause this,

if it dose have one, remove it clean with carb cleaner, let it dry out then give it a shot off duck oil or three in one sray oil,

do not under any circumstance use that orible W stuff as it is NOT a lubricant at all

[chrisb1357]

It does have an idel control valve

[Stickyfinger]

THIS !
so true
"do not under any circumstance use that orible W stuff as it is NOT a lubricant at all"

Try disconnecting the cable at both ends. Does the cable slide smoothly ?> Do the linkages work smoothly by hand and return to the stop ?> Start Engine and try revving it by hand, does it show symptoms still.? try to isolate the problem area..

[citronut]

the other thing if it has one can cause this symptom is the throttle damper ( looks like a miniature tail gate strut ) , which can cause the throttle to stick holding the throttle up/on were it was last revved up to/at,

the fix for this is just remove it completely