Mitsubishi dealer diagnostic health check worth it?

[jahooli]

Hi, I have a misfire when cold and a drone from the back end when at low revs around 30mph, can't get a mechanic to diagnose, drove into mitsi dealer expecting cash to start flying out of my pockets as I stepped over the threshold but it didn't so I carried on walking to reception.
They offered me a full diagnostic and health check with a courtesy car for the day for £85, I thought that was very reasonable.
They assured me they are able to diagnose fully on the legnum.
Any thoughts?

At
Paul

[foxdie]

Misfire when cold could be a number of things. Plugs dirty, HT leads old, coil packs dying etc.

The drone, does it sound mechanical? Is there a fault with your AYC system (red light on dash)?

[jahooli]

Yes I thnk it's mechanical, new tyres, still same, same on corners, same in every gear, a humming/drone under slight load at low revs, no lights, hoping it's not the dif but just want a diagnostic. I really want a thorough health check for the car I'm just wondering if people think Mitsubishi dealer is a good place to get that.
Cheers

[TAR]

I would be asking what they check.

I am not convinced that main dealers know our cars well enough to be able reliably diagnose faults. You may have found the exception to the rule, but I remain sceptical.

It's also possible for you to do your own diagnostic, by reading the codes generated by the ecu. Its quite easy and there is lots of threads about it on here. Try his one as a start - http://www.clubvr4.com/forum/showthread.php?59792-Diagnostic-Checks&highlight=diagnostic+codes

:happy:

[jahooli]

Thanks for that, already had a go at that, no errors. The problem I have is the misfire only happens when damp so its harder to diagnose, by the time I take it anywhere the engine is warm, left overnight too but the weather was clement, clement I tells ya!
Id like them to put audio sensors on the diff and such like which they have said they will do alongside checking the oils.

Just have to hope their diag software is up to the job for the fault codes.

Cheers.
Paul

[jahooli]

Hello,
I just had a look under the bonnet as I heard the missfire (it was damp) there was a spark shooting from the middle lead where it connects to I think the coil pack? This continued until the engine got warm then it wouldnt do it again. I cant see in there fully as my plg injectors are there, I would have to take some stuff off and I didnt get time.
Can anyone diagnose from that short description?

Thanks
Paul

[elnevio]

HT lead breaking down, or possibly the coil pack itself, depending where the arcing is actually happening, at a first guess!

[TAR]

There are a couple of people breaking cars at the minute. I would get a second hand coil pack and lead to test with. Change the coil pack first, as that is the easiest.

:happy:

[Davezj]

if you want to check for break down just get a spray bootle with water in it and lightly mist water on the HT leads and coil packs they should not break down even if they do get a bit wet.
but if they break down then you can see where it comes from.
also do it in a dark place then you can see the sparking brightly light a light show.

[jahooli]

good plan. its booked in for Monday morning, ill let you all know what exactly they do. If they dont diagnose the misfire (it only happens when damp) ill try the bottle method.
Thanks kindly.
Paul

[jahooli]

Hi, an update on the dealer.
Went in to pick the car up today, as you rightly said they were unable to hook the car up to the computer so could not do any ecu fault code diagnostic (despite telling me they could). They basically just did a general mechanical check and road test...oh and they washed and hoovered the car. The best part is tho they didnt charge me a penny!!!
I had a complimentary car for the day and they kindly washed and hoovered the papap. Top job.

i now need a used coil pack and lead.

thanks

[elnevio]

The Mitsi main dealer didn't have a Mitsubishi MUT-III to plug in? Or didn't have the JDM cartridge for it? Very odd!!


But at least you can't complain about everything else being free! :deal2:

[Atik]

I had a similar arcing problem on my car last year. Initially I put it down to having a dodgy O2 sensor, but I noticed the arcs once when I was sorting out the stereo wiring in the engine bay.
Sorted easily with a HT lead change/upgrade.

Incidentally I also had a rumble from the rear of the car which I thought was a dead diff, but Nick Mann managed to diagnose it as a dodgy wheel bearing. Turns out the bearing had a slight bump in its rotation. There was no lateral movement on the bearing so would not have come up as a fault if you just did the wheel wiggle.

I'd say try to get to a garage with a lift, get all four wheels off the ground and put the car in drive and listen out for the noise.

[jahooli]

Thanks, the noise comes and goes, seems to come after a few days of longer runs, im only nipping a couple of miles to work and back each day and I dont hear it, if i do a few longer runs it comes back for a bit which I put down to some sort of temperature thing with the oil. I suppose I have to get all the oils changed.
Ill heat it up and get them to check the bearing also.

[TAR]

Useless Mitsi dealer... still at least they know how to operate a vacuum cleaner!

:happy: