Revs die down when fan kicks in...

[FunkyGibbon]

I've just had the car serviced (and had engine mounts, rocker cover gaskets and fan belt done).

Since I've got it back the revs drop (and stay dropped) when the fans kick in. This happens at idle and under load.

At idle the revs drop to about 300-400 - the car never actually dies just stuggles.

Under load you can feel the engine revs drop when the fans kick in.

When the fans are off no problem at all.

Also, I noticed that when I got the car back the service bods had been in around the ecu/battery area (hadn't put the panel back and the radio had lost it's setting) - so I guess the battery has been disconnected at somepoint.

So I guess this is something electrical - but where to start looking?

Any ideas?

TIA

(and before you shout stepper motor wouldn't that cause problems all of the time, not just when the fans kick in?)



>> Edited by FunkyGibbon on Tuesday 28th March 10:34

[andy-w]

if you have dual fans it draws too much current away from the engine...if you get one of the mod wise dual daul fan control kits then you can wire the fans up directly to the something like the starter motor live and the problem goes...at least it did on mine.

[FunkyGibbon]

andy-w said:

if you have dual fans it draws too much current away from the engine...if you get one of the mod wise dual daul fan control kits then you can wire the fans up directly to the something like the starter motor live and the problem goes...at least it did on mine.

thanks, but why would this only now be a problem post service I wonder?

[andy-w]

cant see why changing either of those would cause the problem...bit of a strange one that???

[cossiemetro]

alternator or battery on its way out perhaps test the battery to see what its being charged at 13.8v should be good anything below 12 and its a worry

[FunkyGibbon]

cossiemetro said:

alternator or battery on its way out perhaps test the battery to see what its being charged at 13.8v should be good anything below 12 and its a worry

I did think about that, they changed the poly belt as well, so if that tension is wrong could that effect the alternator (i.e. not spin it properly) so I'm not getting full charge back to the battery?

It does seem to be worse as time goes on. Time to give the service bods a call me thinks.

[blujay10]

If it was fine prior to the service, suggest you take it back to where it was serviced and see what they say? Failing that a phone call at the very least - most places would much rather hear of potential problems from their customers.........

[FunkyGibbon]

blujay10 said:

If it was fine prior to the service, suggest you take it back to where it was serviced and see what they say? Failing that a phone call at the very least - most places would much rather hear of potential problems from their customers.........

oh indeed I will call them, just wanted to see if it was a quick fix that I could do myself.

[FunkyGibbon]

OK I've phoned the garage and have it booked back in for Thursday. But they suggested I check the vac advance pipe - which I will.

If this is the cause why would it only be a problem when the fans cut in?

TIA

FG

[FunkyGibbon]

fixed!

It is amazing the difference it makes reseating the spark plug caps and having the air intake pipe actually clipped on to the AFM (rather than it dangling in the breeze )

Guess that would explain the flat spot at about 2800 rpm as well.

I really need to look under the bonnet more - at least she pulls like a train again.

Thanks for the replies folks.

[jonathant]

IS the AFM intake pipe removed as part of the service????

[FunkyGibbon]

jonathant said:

IS the AFM intake pipe removed as part of the service????

Doubt it, but it may have been moved when they did the engine mounts and rocker cover gaskets. Easy to catch on your overalls when leaning in to do work - apparently