White exhaust smoke

[Mike Noc]

Yes if you want to ensure your injectors are working as they should get them tested off the car. Also if you have access to a T4 you can check the compression - saves faffing around with connecting gauges up.

[Ducati750cc]

Originally Posted by Mike Noc

Yes if you want to ensure your injectors are working as they should get them tested off the car. Also if you have access to a T4 you can check the compression - saves faffing around with connecting gauges up.

Thanks Mike,yes via a T4, a balance test would potentially show up a cylinder with a problem, also comparing injector delivery quantities could also help, sadly I don't know anyone with a T4 locally.


Yes, the best bet is to get all the 'new' injectors checked which I'll do as soon as I can.


Cheers, Bill

[Jamiewelch]

Originally Posted by Mike Noc

Yes if you want to ensure your injectors are working as they should get them tested off the car. Also if you have access to a T4 you can check the compression - saves faffing around with connecting gauges up.

You can't check compression on a T4. You can check injector compensation and cylinder balancing, but not compression. Just because the car isn't compensating on a cylinder doesn't mean that it is ok. It just means it isn't aware of an issue.

[Mike Noc]

Originally Posted by Jamiewelch

You can't check compression on a T4. You can check injector compensation and cylinder balancing, but not compression. Just because the car isn't compensating on a cylinder doesn't mean that it is ok. It just means it isn't aware of an issue.

It might not be as accurate as using a gauge but you can. The engine turns over with the injectors not firing and T4 checks how the crankshaft speed slows as each cylinder comes up on compression.

[Jamiewelch]

Originally Posted by Mike Noc

It might not be as accurate as using a gauge but you can. The engine turns over with the injectors not firing and T4 checks how the crankshaft speed slows as each cylinder comes up on compression.

If it isn't accurate it is a useless test unless something is seriously wrong. The cranking speed will slow because of compression and the load on the battery massively increasing, with each crank the battery will be weaker and weaker so will skew any potential results. A slight crack that virtually seals up when warm wouldn't be found but is still head gasket failure. You would need to make sure that power is stable and on something to deliver it to the car, using a car battery will have huge voltage dips making it useless. Only using something that can provide 14v at 400-500amps would give anything even potentially usable as a result.

Just take the glow plugs out, do a test then fit new glow plugs (they will be knackered now anyway). Also make sure its a diesel compression tester as a petrol one won't read high enough.

[SteveThackery]

Originally Posted by Jamiewelch

You can't check compression on a T4. You can check injector compensation and cylinder balancing, but not compression. Just because the car isn't compensating on a cylinder doesn't mean that it is ok. It just means it isn't aware of an issue.

Can anyone tell me what injector compensation is? Haven't heard of it before.

[Mike Noc]

Yes at idle speed T4 can determine the crankshaft acceleration after each power stroke, and then compensate by adjusting the amount of fuel from each injector to give a nice even engine idle.

[Mike Noc]

Originally Posted by Jamiewelch

If it isn't accurate it is a useless test unless something is seriously wrong. The cranking speed will slow because of compression and the load on the battery massively increasing, with each crank the battery will be weaker and weaker so will skew any potential results. A slight crack that virtually seals up when warm wouldn't be found but is still head gasket failure. You would need to make sure that power is stable and on something to deliver it to the car, using a car battery will have huge voltage dips making it useless. Only using something that can provide 14v at 400-500amps would give anything even potentially usable as a result.

Just take the glow plugs out, do a test then fit new glow plugs (they will be knackered now anyway). Also make sure its a diesel compression tester as a petrol one won't read high enough.

I didn't say it wasn't accurate but that it won't be as accurate a gauge test and it is an official comparison test. As for the variations in cranking speed and battery load, they wouldn't affect an individual cylinder being down on compression (or two if the gasket has failed between them) because they would show up as low compression compared to the rest.

On the M47R which is what we are discussing here, head gasket failure is virtually unheard of. Stuck glowplugs aren't though. In a 20+ year old engine where they have never been touched before they can seize in place and break when you attempt to get them out and then you are in all sorts of bother.

Each to their own, and if you don't rate the test then don't do it, but I'd recommend anyone with access to a T4 to try that first before touching the glowplugs if they suspect a compression fault, and of course they can check injector compensation, any stored faults etc at the same time.

The path is System diagnostics: Engine Management: Real Time Display: Engine Roughness: Cylinder Balancing Status: and then with the engine stopped for compression test and running for idle speed variation.

[Alex30013k]

I have a the same symptoms. Cold start bad misfire. White smoke when you rev 1.5 - 2k. Some days are worse than others.

When warm it's OK. But you can feel a misfire when driving around 2k.

I have replaced every thing. New injectors etc.

I am fitting a new engine next week thats done 30k, my car is is 350k,

Have a google for freelander 2k misfire. - no fix for it.