screwy 406

[jhammond1]

Hi everyone, bought a cheap unloved 406 last year which has developed a few issues.

1. Engine runs cold, temp guage never goes above 80 unless in traffic and generally stays closer to 70, would assume just thermostat sticking if not for the other issues.

2. Radiator light came on a few weeks into ownership, checked coolant level and fine and no visible leaks on rad. Whilst doing a service a couple of weeks later heard pressure relief from expansion cap after running engine.

3. Replaced expansion cap, frequently hear it releasing pressure after running car and have to top up coolant very regularly.

4. Car doesn't like starting in the cold but always does eventually.

5. No gunk in coolant or oil, getting 45mpg over mostly motorway but also some very hilly single track roads, car runs fine.

6. Heaters not great.

7. Its an 03 plate 406 hdi 2.0 110 with 115k on the clock, appears to have been poorly maintained if at all.


From various research its sounding pretty head gaskety but im hoping someone will be be able to tell me "mate its just the thermostat, change that and freshen the coolant you'll be good to go".

The car only cost 495 and if she lasts another 1500 miles and or to may I'll be happy. If its definitely the head gasket im not going to fix it and I do not want to throw money or time into it but if there are any easy checks or changing the thermostat could solve the myriad of problems above I would greatly appreciate the advice.

[PeterN]

I fear that at least one of the problems is a leaky head gasket, they are generally much longer lasting than the XUD ones and I have never personally had one fail but I have come across a couple when looking for a car, first thing I always check. You could try running it with the filler cap loose, if the gasket is not to bad this will allow the pressure to escape and not blow the water out of the overflow which is probably where its going. If the gasket is very bad it will blow the water out of the filler. Also the harder you drive it the more water you will lose, take it steady, particularly keeping the revs down.

This could also be causing the poor heater output as if there are gas bubbles in the system they will tend to collect in the heater and displace the water, you could try bleeding the heater on the pipes that go through the bulkhead.

If the temperature is reaching 70c that should be sufficient to give good heat, in the temperatures we are having at the moment mine rarely reach normal, if it will stay at around 70c I would suspect that the thermostat is OK.

Peter

[jhammond1]

Hi peter

Thanks for the speedy response, I shall try running with the cap loose, that's a very good idea.

Pretty sure the head gasket has failed then, I check the coolant before every journey which at the moment is 37 miles and I'd say I have to put in around 100-250ml of coolant about 75% of journeys so not great but not roadside recovery levels yet and car has never seen 90degC.

If the car lasts another 1500 miles it won't owe me anything as I bought it due to the amount I was spending on fuel on my other car and after another 1500 miles it will have saved me £500 in fuel. Would have been nice to keep it going though as I actually quite like the car.

Cheers again, James

[trufflehunt]

Hi peter

Thanks for the speedy response, I shall try running with the cap loose, that's a very good idea.

Pretty sure the head gasket has failed then, I check the coolant before every journey which at the moment is 37 miles and I'd say I have to put in around 100-250ml of coolant about 75% of journeys so not great but not roadside recovery levels yet and car has never seen 90degC.

If the car lasts another 1500 miles it won't owe me anything as I bought it due to the amount I was spending on fuel on my other car and after another 1500 miles it will have saved me £500 in fuel. Would have been nice to keep it going though as I actually quite like the car.

Cheers again, James

My HDI 110 cost £495, at 150,000 miles, and lasted just under 4.5 years, and a further 30,000 miles. Like several other oldish cars I've owned the head gasket was a little weak. The cooling system was fine in normal running, and would only pressurize in extreme conditions. eg Porlock Hill in Somerset. The coolant would need topping up with about 100 ml every 3 or 400 miles. I used a bottle of K-Seal on this ( £10 ). No further loss of coolant.

[jhammond1]

Might be worth trying a bit of k seal. Now you mention it I've been driving up a mountain in the brecons every weekend and thought it was getting worse but could just be due to the driving conditions, in fact now that I think of it, it definitely uses more going up the mountain than coming back down. Fingers crossed for 4.5 years happy motoring!

[trufflehunt]

Might be worth trying a bit of k seal. Now you mention it I've been driving up a mountain in the brecons every weekend and thought it was getting worse but could just be due to the driving conditions, in fact now that I think of it, it definitely uses more going up the mountain than coming back down. Fingers crossed for 4.5 years happy motoring!

Instead of crossing your fingers, you could try making an effort and giving the car a decent service.

[jhammond1]

I've done an oil change, pads and aux belt (minimum basically)

Car has no service history and any money I put in could easily be lost. To service everything that should be done would probably add up to around £500 (especially if I got cambelt done which I wouldn't want to do myself) and would be a waste if the head gasket is on its way out which it sounds like it is.

If the car still runs when the mot is due in may I might put a bit more effort into it but I think its a bit of a lemon and don't want to end up with a lot of time and money invested.

[PeterN]

If you take the top cambelt cover off you can have a look at it, if it looks in fairly good condition it will probably be OK for a bit, if it looks as though its suffering it would be safer to change it although I understand the principle of throwing good money after bad.

I bought the two estates I have now for £350 and £400 respectively, the latter has now covered over 200k, about 20k+ of that since I had it, I have had no serous problems at all, I have changed the cambelt and water pump though which cured the slight water loss I had.

There are still plenty out there at about that price, if you want to know how to check the head gasket let me know. My opinion of the 406 is that it was the last good Peugeot, I have had three 2.0. Hdi estates now and they never seem to go wrong.

Peter

[jhammond1]

Hi Peter, I was planning on getting the cambelt done after driving it for a few months to see if it was a keeper but having a look under the cover is a good idea and the thought had crossed my mind but I've not got round to it as I've got a lot on at the moment but I assume it's an was job so might have a look this weekend.

I did run the engine up with the cap off to look for bubbles and didn't see any but not sure I ran it for long enough. To be honest I'm resigned to the fact that the head gasket is leaking and probably going to look to replace the car when I have the time and money to do so. It nearly didn't start on Sunday after fishing in the brecons where you get no phone signal and the nearest pub to borrow a phone is about a 4 mile walk so would rather have something I can trust a bit more.

Cheers for the help and advice.

James

[jhammond1]

Hehe, handbrake cable has snapped too now.

[jhammond1]

Car in for sale section, £110.

[PeterN]

Oh dear! If its one of the short ones its fairly easy but the full length one is a bit of a pain as you have to remove the centre conole. I drove an XM for about 20k miles with the filler cap unscrewed and very rarely had to put water in it although with the cap on it blew it out every time I put my foot down hard.

Peter

[jhammond1]

I wouldn't have minded doing the handbrake cable except for the fact I can't get one of the back wheels off because it has one of those stupid shearing locking wheel nuts. I'd never heard of a shearing locking wheel nut until I used my trusty locking wheel nut removal tool.

Head gaskets getting worse as well, plumes of white smoke engulf all unlucky enough to be stuck behind me at traffic lights. Cutting my losses and selling before it breaks down.

Not too fussed as it was cheap and i actually looked to see if there were any 406s for sale near me to replace it (preferably better cared for) but was nothing around so bought my first ever saab instead. Hopefully this will last a bit longer!