Pulsing idle

[BaroqueMoon]

Hi, my 2.6 petrol has started to behave rather strangely. At idle it sometimes pulses from 750 to 1500 revs every couple of seconds.
Any ideas?

[SD1too]

Hello Matthew,

I think you mean 2.5 litre engine! ;)

Have you just had an oil change, or topped-up the oil level?

Simon

[sandman jim]

Hi, my 2.6 petrol has started to behave rather strangely. At idle it sometimes pulses from 750 to 1500 revs every couple of seconds.
Any ideas?

hi..when i had a yaris years ago mine did that it was the egr valve needed cleaning when that was done it was perfect,,i hope this has been of some help to you,, james:}

[Mike Noc]

Don't spend too much time looking for an EGR valve on the KV6. ;) :D

[BaroqueMoon]

Hello Matthew,

I think you mean 2.5 litre engine! ;)

Have you just had an oil change, or topped-up the oil level?

Simon

Oops yes 2.5.
Last oil change was about 2000k ago.

[Phil-T4]

Check for a air leak around the manifold and throttle body, have you had the VIS motors out at all?

[BaroqueMoon]

Check for a air leak around the manifold and throttle body, have you had the VIS motors out at all?

I shall. I have no way of testing the VIS motors :/

[SD1too]

Last oil change was about 2000k ago.
2,000,000 km ago? :eek: You must have the highest mileage car in the world! ;) What's the real figure please?

Matthew, check the oil level using this (http://www.the75andztclub.co.uk/forum/showpost.php?p=1233152&postcount=46) method. Is the dipstick reading above the maximum mark.
If your sump is overfilled, we're told by an ex-MGR design engineer that this increases the amount of oil drawn into the inlet tract via the crankcase breather system. Since taking his advice and lowering the amount of oil in my sump, the instances of idle pulsing on my car have reduced substantially.

Regarding PhilT4's suggestion, I'd say that the first place to look is at the breather hoses underneath the engine acoustic cover (two 8mm screws and lift it off). The hoses frequently break at the junction with the 'T' piece.

Simon

[BaroqueMoon]

2,000,000 km ago? :eek: You must have the highest mileage car in the world! ;) What's the real figure please?

Matthew, check the oil level using this (http://www.the75andztclub.co.uk/forum/showpost.php?p=1233152&postcount=46) method. Is the dipstick reading above the maximum mark.
If your sump is overfilled, we're told by an ex-MGR design engineer that this increases the amount of oil drawn into the inlet tract via the crankcase breather system. Since taking his advice and lowering the amount of oil in my sump, the instances of idle pulsing on my car have reduced substantially.

Regarding PhilT4's suggestion, I'd say that the first place to look is at the breather hoses underneath the engine acoustic cover (two 8mm screws and lift it off). The hoses frequently break at the junction with the 'T' piece.

Simon

Ah but by 2000k I meant 2000 kilometres :) Sorry for the confusion.
The oil level is a tad under the maximum mark.
I'll be checking the breather hoses. I hope thats all it is and thank you for the information. I wasn't sure where to start as my searching here only told me about oil burners.

[BaroqueMoon]

I wont be able to attempt a fix for a few days (long story) but will report back as soon as I can.

[Stag>75]

2,000,000 km ago? :eek: You must have the highest mileage car in the world! ;) What's the real figure please?

Simon

Simon

He was talking Strine. If someone here asks how far Sydney is from Melbourne the answer is "bout 900K"

John

[SD1too]

Thanks John. Now you put it like that, I don't know why I didn't get it in the first place. Ah well ... :getmecoat:

Simon

[BaroqueMoon]

Finally got a chance to check my car. No problems found and the pulsing idle has stopped.
What the?

[chris75]

Does having the aircon on or off make a difference ?
Low pressure will make the compressor keep trying to cut in and raising the revs momentarily :shrug:

[BaroqueMoon]

Does having the aircon on or off make a difference ?
Low pressure will make the compressor keep trying to cut in and raising the revs momentarily :shrug:

No, no difference with aircon. Intermittent faults are so frustrating.
Ah well. I know where to start if it crops up again.
Thanks :)

[stocktake]

Mine does this sometimes but only in very warm weather, Last couple of times I lifted the bonnet whilst it was doing it and gave it a small blip on the throttle. the idle returned to normal, on a second occasion i pressed on the throttle linkage and again it returned to normal. I think there is a slight wear on the throttle assy.