Renault Kangoo - help with engine problems

[the snooper]

Looks possible, I just undid the electrical connection. It will either rev hard but hunt at the top end of the revs, or it just wont rev (regardless of throttle position). It's become a fine art driving to and from teh test centre changing gear as fast as possible with limited revs and getting as fast as 25mph in 5th!

Cheers

Peter

could also be worth checking throttle position sensor

 

[roofman]

A rare few of bucket and shim tappets actualy go tighter with age..the cam lobe forces the middle to stretch to the edge and makes it tighter thus lifting the valve off its seat.

 

[Kayos]

Different car but once had a vectra with the exact same symptoms, ended up being a knackard timing belt tensioner, causing the knock sensor to stick the engine in limp mode after a few seconds

 

[AndyStobbs]

A rare few of bucket and shim tappets actualy go tighter with age..the cam lobe forces the middle to stretch to the edge and makes it tighter thus lifting the valve off its seat.

Or the valve seat and valve head simply wear...

 

[puffernutter]

An update. It was at a specialists for the last few days and they even had an external specialist look at it! Suggestions are that it is probably not electronics related, but more likely a burnt valve or cracked manifold. Also at 140k miles, probably not worth spending any more money on it.
Another expensive lesson learned!
Cheers
Peter

 

[AndyStobbs]

You could verify that yourself though. Don't take it as gospel just because an external specialist deemed it so.
Not to detract from the skills of other mechanics but we can all be wrong and it'll cost you nothing to do a compression test.
You could probably run it on propane to smooth it out while you mess around trying to isolate 1 weak cylinder.

 

[puffernutter]

Dry cylinder test (will do wet tomorrow). #1 is next to Gearbox (typical French)

1 - 150psi (10.7 Bar)
2 - 118psi (8.4 Bar)
3 - 160psi (11.4 Bar)
4 - 172psi (12.3 Bar)

From what I can find out 8 - 12.5 Bar is acceptable. However as #2 is so low and the plug was a different colour and had deposits on the outer electrode, that's where I think I should look.

If I do a wet test and the readings stay relatively the same, I can rule out rings and then it probably is a burnt valve?

Would this cause the rough running?

Cheers

Peter

 

[AndyStobbs]

Would certainly investigate number 2 further. Take the rocker cover off and measure valve clearance, if you have a feeler gauge its just the time factor.

I would go as far as to say you've just ruled out a cracked manifold as that wouldn't affect comp tests.

With many modern petrol ecu the injector can be disabled to prevent fuel injection to a missfiring cylinder. Does it run well from cold for a minute or two?

 

[normspanners]

Get an old plug and smash the ceramic out of it weld a hose tail to it then put engine on tdc with h/brake on in gear then fit the plug/ hose in the number2 then blow regulated air pressure in and see where the air is coming out my guess is the exhaust valves but if you take the oil filler cap off then listen to how much is passing the rings compare with the good ones
if the cylinder rings/piston is leaking it should normally be burning loads of oil, that is usually worse when engine is cold.
There are ways around an oil burner by fitting short reach plugs to help keep them clean.
The valve clearance should be---- inlet .1mm -----ex .25mm done cold, if valves have gone tight caused by valve seat wear/erosion (it is nothing to do with the tappets) at the point of just starting to hold valve off, doing an oil/wet test will also tend to help seal it and disguises the results .
The situation only gets worse as the valves warm up and expand.
the other poss is the injector on number two is weeping and fueling up the plug and washing the bore of oil.
You can test that by swapping the injector to another cyl if the problem follows the injector ie test by plug colour then it could be the injector.

 

[the snooper]

put engine on tdc.

make sure its on compression stroke not exhaust

 

[Gavin_d]

I did a cylinder compression test once and the car was in gear without handbrake on. Made the car move forward a little lol

 

[normspanners]

I did a cylinder compression test once and the car was in gear without handbrake on. Made the car move forward a little lol

I would think it did----------- the starter motor normally does that.

 

[Gavin_d]

I would think it did----------- the starter motor normally does that.

I didn't think it would be that powerful lol. Had my knees on the bumper and it nearly made me fall over backwards lol.

 

[AndyStobbs]

Nearly broke my wrist doing a leakdown on a motorbike once.

 

[normspanners]

Nearly broke my wrist doing a leakdown on a motorbike once.

WOT you didnt put the hand brake on?

 

[normspanners]

make sure its on compression stroke not exhaust

YOU ALLWAYS HAVE TO CORRECT ME !!!


Normally a good job

 

[the snooper]

YOU ALLWAYS HAVE TO CORRECT ME !!!


Normally a good job

Can't think who your on about there norm

 

[puffernutter]

Right, a bit more time today and the rocker cover is off, I'll measure the tappet clearances (probably Tuesday) and report back.I do like the idea of putting compressed air in there. I don't have any spare spark plugs, so I'll see if I can turn something suitable up.

Cheers

Peter

 

[roofman]

Right, a bit more time today and the rocker cover is off, I'll measure the tappet clearances (probably Tuesday) and report back.I do like the idea of putting compressed air in there. I don't have any spare spark plugs, so I'll see if I can turn something suitable up.

Cheers

Peter

I adapated an old compression gauge for a filler pipe...take out the tire valve with a generic valve key (entry side of tester) and take off the gauge from the other end which in my case was the same thread diameter and form as a female ended airline connector...screw the pipe into the plug hole and connect up to the airline from your compresser and wham bam thankyou maam...

 

[normspanners]

I adapated an old compression gauge for a filler pipe...take out the tire valve with a generic valve key (entry side of tester) and take off the gauge from the other end which in my case was the same thread diameter and form as a female ended airline connector...screw the pipe into the plug hole and connect up to the airline from your compresser and wham bam thankyou maam...

they are also very handy for changing valve stem seals or broken valve springs without removing head.