A real head scratcher... 405 problems...

[Gigagator]

Hi all,

I have a 1995 Peugeot 405 GLX. It is the 1.6 XU5 engine and I've been having so much trouble lately. This is going to be a long and tedious explanation but I'm really hoping you'll stick with me and help me diagnose my problem.

About a year ago the engine started to run rough, idle speed would be all over the place, it was chuggy, fuel consumption was right up and the engine check light was coming on. I eventually discovered that the hose had come off the MAP sensor. I reconnected this and all the problems went away.

However, a couple of weeks ago all the symptoms came back twice as bad - it stalls frequently now and is almost undriveable. Naturally, the first thing I did was check the hose to the MAP sensor - it was attached but had a split at the end.

I cut off the split part of the hose as it was only on the end and reattached it but the problems did not go away. I have noticed though, that when the hose is taken off the MAP sensor, the car runs beautifully. When it is reattached to the MAP sensor, the problems return.

My first thoughts were a dodgy MAP sensor but I'm not sure on that one. A mechanically minded friend said that the engine has a gauze or filter somewhere that could be clogged with oil and filth and clearing it might help - sort of like when a person has a cold and they get all bunged up. I don't know what he was on about or where this part is so if you could shed some light on this that'd be great.

Another thing to mention would be that the handle came off the dipstick about a year ago too so it has been running all year with oil occasionally spraying out of the dipstick tube.

The old dipstick said oil was on MAX. The new one which I bought from a Peugeot dealership reads MINIMUM oil. The dipstick is definitely the right one for the engine - it turns out the handleless dipstick was being pushed too far in so giving a false reading.

Therefore, the car has been running for a year with oil on the minimum mark - could that be related? The whole experience with the two varying dipsticks though makes me weary about which one to trust.

Being so close to Christmas means money is really tight. I simply cannot afford to take this to a mechanic and pay extortionate amounts of money to check everything over. If somebody could suggest a likely problem area that I could check this would be a great help.

I understand though that this could be anything from a dodgy spark plug to the head gasket going. If it is the head gasket, I may just sell the car. I can't afford to have that replaced.

It's such a shame because the car is great and only done 70k miles.

Please help me with this problem! It's so stressful it's even causing me to lose concentration at work. Many thanks!

[chopper1192]

I could be wrong, but I didn't think and Xu5 of that vintage had a MAP sensor, but...?

Your chum could be right. Strip and clean all the breathers and PCV filters. If these clog they can cause lumpy idle and running probs. Similarly, a strip and clean of the throttle body may be in order, especially if the breathers were gunked up. Once clean, get the base idle set up on a gas analyser and, hopefeully, voila!

Hopefully it's not HGF, but if it is then weigh the cost of a few hundred quids work on an otherwise good car, against the likelyhood of ending up with a snotter for the same outlay, which would itself likely need money spent to make it straight.

And finally, provided the oil was on and not below the min mark, it should be fine. A quick compression test will confirm this, but by now I'd have though it'd rattle like a Fiat interior if it had been starved of lube for that long.

[Gigagator]

Thanks for the reply chopper.

It's definitely the MAP sensor. She may be old but she's got it all - fuel injection, AN airbag, aircon!
I wouldn't think its HGF - apparently a sign of that is white mayo stuff? Not a trace of that anywhere.

Could you just clarify the possible location of these breather/PCV valves and what they look like? How many are there? Also, can the job be done without specialist equipment?

I can't get hold of the mechanic friend that suggested this cause of the problem so I will try and do the work myself if I'm confident enough.

Thanks again.