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HDi Cold starting rough...

Posted: Thu Nov 25, 2010 9:02 pm
by EvilTwin
The cold weather seems to be giving my 406 some rough running while the engines cold. For the first min or two you need to run it at slightly faster than idle, just to maintain the engine running.

Soon as its been running for 5 mins and gets warmer the engines fine, just that cold start things causing problems.

I'm thinking its probably the glow plugs, but is there anything else I need to pay attention to? like other sensors etc?

Is checking the glow plugs just a question of using a multimeter on the plugs to check they're getting voltage, or is there more to it? (been a while since I've done anything more in-depth than fitting parking sensors)

Re: HDi Cold starting rough...

Posted: Thu Nov 25, 2010 10:08 pm
by poddack
glow plugs! you could check the resistance, don't know what it should be, but it will be very low! i'd swap 'em, first thing that causes a diesel to hate cold mornings.

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 12:42 am
by FarmerPug
the cold morning start
the one time owning a diesel isnt fantastic.

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 7:36 am
by Welly
When it was -5degC or more mine used to 'miss' a bit for the first 30 seconds and blow a bit of blueish smoke but then settled down.

Testing to see if power is going to the glow plugs first is a good idea. To be honest the HDi doesn't need glow plugs to start as much as old diesels do but that's not to say they don't help. Replacing them never seems to come up on this site but be warned - they can snap off!

If I was you I'd try some injector cleaner first and what about your fuel filter? when was that changed?

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 8:03 am
by FarmerPug
vw tdis sound terrible in the cold morning start

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 8:24 am
by Welly
That's because they are terrible.

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 8:25 am
by FarmerPug
i didnt want to be the controversial one who would say that but yes i agree they are awful

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 9:20 am
by EvilTwin
Thanks peeps, I'll get hold of a filter, and some injector cleaner, then have a look at the glow plugs this weekend.

Any recommended injector cleaners out there or is Red-ex Diesel OK?

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 9:24 am
by FarmerPug
red ex is good yes, smells bad mind so dont spill it on your clothes very hard to get rid of the smell.

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 9:55 am
by Gary406
all cars have a cold start moment,

mine also misses a beat for a few seconds in these winter months in summer its spot on , as well as it sounding like farmer jiles starting his tractor up to do a days plowing

gotta love the old diesel engine noise

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 10:27 am
by puggy
As welly said , my HDI misses for a little while in this cold weather on start up
nothing unusual though . I've driven a awful lot of diesels and they all did the same
in really cold weather even big trucks , and it should be remembered the heater
plugs only work for the initial start up then go out , it then relies on the heat off
combustion to to fire the mix so if the engine block is really cold it takes a little
while to do this efficiently . Gone are the days when you had to put up with the
diesel waxing and you had to wait till mid day before it would start or put a blow
torch over the tank :shock:

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 1:33 pm
by mjb
406executiveHDI wrote:vw tdis sound terrible in the cold morning start
Welly wrote:That's because they are terrible.
406executiveHDI wrote:i didnt want to be the controversial one who would say that but yes i agree they are awful
Mine sounded a bit clattery for about the first 10 seconds this morning (-5c) but it fired up straight away. Didn't have to pour a bucket of boiling water over it, or wait for glow plugs to do stuff or anything!

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 2:02 pm
by Welly
We'd never reach the end of the "which is best" debate on here........"I like HDi's but then again I like VAG's too"......... :cheesy:

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 2:25 pm
by Captain Jack
My HDi started up on 2nd turn in -3C at 6am! I just wish the heated seats and the blower heater warmed up this quick :|

Re: HDi Cold starting rough...

Posted: Fri Nov 26, 2010 4:51 pm
by jasper5
My Expert van (2.0 HDi) has begun this problem, I will look at it in the morning and post my findings.