Hi guys. I thought I would ask here first before taking car to the garage to have a rough idea of what might be wrong.

Couple of weeks ago the 'glow plug light' came up when starting the car. It stayed on for several minutes and then went off. When it was on car was in a limp mode, had limited power and was slow in building up the speed. As the light went off I thought problem is gone, but then same thing happened next time I started the car up. There were I think two occasions that it didn't come up - when engine was still warm and car had been off only for few minutes. I thought that it could be glow plugs, but now reading on the Internet it looks like it may be anything. I connected OBD II reader today to see whether there are any codes coming up - nothing on live codes, only few old ones including P1250 fuel prc solenoid, P0120 throttle sensor and P1542 - undefined. As I said these were codes saved in memory and not 'live' ones.

Could it be glow plugs? As the light stays on only for few minutes and it never came up any other time, but start up. Or maybe egr valve needs cleaning/replacing? It's quite a coincidence that day before light came up we filled car up with better diesel (shell nitro one) rather than supermarket one.

I would really appreciate any help. I know you probably won't be able to fix my car as it needs diagnostics to be run, but just thought I'd give it a go and ask here first to have sort of idea of what they talking about at the garage.

Thanks a lot.

Ann

I'm not that clued up on cars or diesels but my guess is that the glow plugs would need changing first (probably he cheapest option). I'd also clear the codes and see what other codes come up after a bit of driving.

Normal 1 in relation

to EGR sticking ought to be P1412 &

to Glow Plug Relay ought to be P0384

will the OBDII clear the stored codes ?

I cleared the stored codes (took pics for reference, just in case). Light still stays on at the start up. I guess it's either driving for a bit and waiting for new codes to come up or just passing it straight to garage to run diagnostics.

Had a read through other various posts

There would appear to be a temperature sensor in the "glow plug" circuit that senses when everything is warm enough to run properly

It could well be that the glow plugs themselves are not getting properly hot or the sensor is not properly detecting the temperature.

Think in both cases that you may not get DTC's as although the sensed values aren't correct they are probably within the range that won't cause a fault code

Do you have any diesel fuel injection (Bosch) specialists near you ?

Just had a look on Google and yes there seem to be a few garages in and around Milton Keynes that specialise in diesel fuel injectors testing and repairs.

Edit:

Just read about fuel injectors. And forgotten there was also one more code stored - P0303 cylinder 3 misfired.

Be careful removing them I attempted to do my glowplugs today and the first one snapped its half threaded and the top has snapped off, by the looks of things I have myself a nightmare!

@Richbaker I think I may just leave it to car mechanics. As you said I wouldn't like to snap one and knowing how clumsy I can be sometimes, it's just safer and probably cheaper.

Well, got the car booked for Monday morning. We'll see if changing the glow plugs help. After that I think I'll see fuel injector specialist as recommended by Richard. I'm guessing replacing injector won't be cheap...

when the glow plug light is off does it run close to normal. If so then I'm not convinced there is an underlying problem with an injector especially if no injector (directly) related codes came up

Yes, when light goes off car seems to be running normally. Thank you Richard.

Just a quick update. As Richard suggested limp mode was caused by glow plugs. Replaced all 4 of them and also changed fuel filter. They deleted fault code and car is back to normal now. Thanks a lot for help.