rob1miles said:
The killer is difference between cylinders. I called the tech department at Perkins, they were very helpfull. The guy said that with old diesels they did not look at the compression figures in absolute terms, they found many would run fine with 250 - 300 even if they were hard to start, but more than 50 psi differnce was between cylinders was a sure indicator of trouble. Mine had 100 psi differnce and he was right.
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exactly, 10% difference is the usual bench mark
 
Turboman said:
Agree completely. we never used to compression test old engines. We just used to start them up, and slacken the injector unions one at a time, to diagnose which was the weakest cylinder. Then try and rectify the fault, starting with simple stuff like the tappets, and going to engine wear of none of the simple things worked.
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I have acquired a 2.25 that is out of the vehicle and has not been run for a few years, where as it was reportedly a good engine, and still turns (feeling the compression) by hand, I have not seen it running. Because of this I was looking to perform some basic tests before trying to start it. I do not want to strip it all down if not needed, but am happy to do so if that is indicated.
 
If it starts and runs ok with expected mpg and oil consumption, I wouldn't worry too much about compression tests. My petrol readings are all over the place but he runs sweet enough. A £30 compression test kit will run into hundreds of pounds for the neurotic owner.

Col
 
Colthebrummie said:
If it starts and runs ok with expected mpg and oil consumption, I wouldn't worry too much about compression tests. My petrol readings are all over the place but he runs sweet enough. A £30 compression test kit will run into hundreds of pounds for the neurotic owner.

Col
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That is my current problem is I want to ckeck it pre-starting as it is a new to me engine which has not run for a while. These are hard enough to start fitted to a vehicle and running regularly so want to give it the best chance possible to start and bench test without unnecessarily stripping it all down.
 
As long as the fuel system is free of air and the battery is really good, it should start ok. It's always a bit exciting starting an engine for the first time, good luck with it.

Col
 
dag019 said:
That is my current problem is I want to ckeck it pre-starting as it is a new to me engine which has not run for a while. These are hard enough to start fitted to a vehicle and running regularly so want to give it the best chance possible to start and bench test without unnecessarily stripping it all down.
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That would be my approach. Get it going, either on the bench or in a vehicle. It is fairly likely it will run OK, if it doesn't, take it from there.
 
If the heater plugs are working ok it should start.
If it starts all is well...dont expect to much from a 2.25d...done 200.000miles with one with a full rebuild at 100.000mls.
 
nickjaxe said:
If the heater plugs are working ok it should start.
If it starts all is well...dont expect to much from a 2.25d...done 200.000miles with one with a full rebuild at 100.000mls.
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It is getting new glow plugs before trying to start it.

I have a 2.25d in my series 3 so know what they are like. This is for a fiends series 1 which had a Peugeot engine fitted but decided the throw all its rods!

Turboman said:
That would be my approach. Get it going, either on the bench or in a vehicle. It is fairly likely it will run OK, if it doesn't, take it from there.
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Hoping that with new glow plugs and lift pump it should start with a good battery also being jumped from another vehicle.
But will check compression, valve clearances and change the oil before trying to get it going just to give it the best chance of running.
 
dag019 said:
It is getting new glow plugs before trying to start it.

I have a 2.25d in my series 3 so know what they are like. This is for a fiends series 1 which had a Peugeot engine fitted but decided the throw all its rods!



Hoping that with new glow plugs and lift pump it should start with a good battery also being jumped from another vehicle.
But will check compression, valve clearances and change the oil before trying to get it going just to give it the best chance of running.
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If you have glow plugs, clean fuel, and spin over quick enough, they usually start. Tappet clearances are always worth a look too.
 
dag019 said:
How would be best to do that, Spin it over without fuel or is there a way on doing it manually?
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I've always put a few drops in each cylinder a day or two before the planned start up and then turn the engine over without fuel or in the case of petrol engines, with the HT lead removed. An oil guage helps show when the oil pressure is good.

Col
 
I always take the plugs out or loosen the injectors then put jump leads on and crank until the oil light goes out, plus a few drops of oil into the cylinders.
 
rob1miles said:
I always take the plugs out or loosen the injectors then put jump leads on and crank until the oil light goes out, plus a few drops of oil into the cylinders.
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That was what I was planning on doing, rigging a temporary oil pressure light to bench test the engine before fitting and just crank it over until it went out. After everyone’s advice on here I will also drop some oil down the cylinders before refitting the glow plugs
 
Just a small amount of oil down the bores and keep track of how much, you don't want to hydraulic lock it.
 
Can anyone point me in the direction of a suitable adapter (or give me the correct sizes to search for) for the 5mb 2.25 diesel for a compression test. typically the set that i bought does not have one that will fit :mad:
For the price of the set, if someone can point me to a cheap set with a suitable adapter I would also consider that. What I am trying to avoid is all the effort of making my own from an old plug if at all possible.

There is another kit (£26) including these: Glow Plug Adapters Size: M10 * 1.0/91 mm, M10 * 1.0/119mm, M10 * 1.0/113mm, M10 * 1.0/102mm, M10 * 1.0/83mm, M10 * 1.0/135mm, M10 * 1.25/64mm, M12 * 1.25/47mm, M22 * 1.5/118mm

Are any of these suitable?
 
If you have and old glow plug, pig tail punch out the middle then tap the hole to take one of the fittings, save you buying another test kit.
 

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