6.2 rebuild or not???

[brighty]

OK, I'm in Australia and in need of some info on where to start diagnostics on my 6.2 donk. There's very limited info on these engines here in OZ so am just trying to get all the info I need before I put the truck in the shed for a while to be worked on.

Firstly... it seems to have lost a fair bit of power in the past year or two.... most noticably in the last 6mths as I've been taking it away on long trips loaded up with gear. Due to a snapped main shaft in the IP, I had to replace it approx 2yrs ago and all was well with no probs. I haven't however had the $$ to get the injectors done and was thinking this may be the place to start and get them done first. It does blow a fair bit more smoke now than it did before... more of the black/blue smoke when warm but blue/grey on start up(see here
http://au.youtube.com/watch?v=HtAnnIiBoJg
http://au.youtube.com/watch?v=0Odo7FiMWiU

the other things i wanted to know are:
- Good Oil Pressure range at idle?? (once warm)
- What's a good &/or bad compression when doing a compression test.
- How do you do a compression test??I know the basics but how am I able to do a compression test without the engine starting???

If there are any other things to test before concluding it needs a rebuild, feel free to throw me some ideas/things to check.

Will post up a couple of pics of my truck & engine soon.

Cheers,
Brighty.

[jogl]

Brighty:

I would do a compression test before I did anything else. Diesel compression testers can be had for cheap. I bought one for about C$50 (I guess that would be about $40 Australian) from Harbour Freight. It is a cheapy but it tells me what I need to know and came with adapters for just about everything (except for Perkins, I had to make my own adapter out of an old injector).

As I recently was reminded the easiest way to check these motors is to take out all of the glow plugs and screw you compression checker into one glow plug hole at a time.

You want to see 300 to 400 psi.

If you have a lot of miles and are seeing black smoke it sounds like your rings are wore and you are burning some oil. Is you oil consumption up? How many miles on the motor?

Could also be oil getting past the valve stems, but in my experience when that happens you see oil in the exhaust manifold (and thus all over) and you see puffs of smoke when oil drips into the combustion chamber.

Guys who are more knowledgeable on these engines are sure to chime in but, as I said, I think that the first step would be a compression check.

Good Day,
JP.

P.S.: That is an interesting looking "donk" you have there, I can't wait to see the pics.

JP.

[Robyn]

The 300-400 PSI comp is right on. As long as there are none lower than 300 you should be fine.
To do the test without the engine starting, unplug the electrical connector to the IP
Depending on the rig it should be a large red or pink wire on top of the IP

Crank the engine so you get 4 pulses on the cylinder being tested.
The glow plug hole is the best access point and adapters are readily available.

The injectors lose "POP" pressure over time and the spray pattern goes south as well.

If the IP you got for a replacement was used there is no telling what shape its in.

Over time the advance piston and a few other things wear out and then the performance goes away.

With low pop pressure and poor spray the injectors can cause very poor performance and dismal mileage.

Avoid the ebay sellers of injectors unless you know them.

If the compression is good things should be fine.
Another thing to check is the blowby. With the engine at idle speed remove the oil fill cap and observe any smoke/vapor coming out.
This should be minimal and with just a little rpm added it should go away totally.

Oil pressure should be about 20 PSI hot at idle using 15-40 oil and run down the road at about 40 PSI.

With any reasonable care these engines will run a long time with minimal issue.

The IP and the injectors are good for about 100K miles even with good clean fuel.

The cleaner the fuel the longer they last.

The factory fuel filter is a very poor excuse for a filter and a good racor with a 2 micron filter is far better.

Hope this helps

Robyn

[brighty]

The 300-400 PSI comp is right on. As long as there are none lower than 300 you should be fine.
If I do come across one that is lower than 300PSI, does this mean rebuild time??? Is there any other remedy.... new rings maybe??


The injectors lose "POP" pressure over time and the spray pattern goes south as well.

If the IP you got for a replacement was used there is no telling what shape its in.

Over time the advance piston and a few other things wear out and then the performance goes away.

With low pop pressure and poor spray the injectors can cause very poor performance and dismal mileage.

Avoid the ebay sellers of injectors unless you know them.
The IP was one that was rebuilt with my dud one being a core unit, there are only two companies here in OZ that I would really deal with, Linquip or Brunswick Deisels.. the latter is where I got my IP from. The service guy couldn't have been more helpful and kept me on the phone whilst I was doing what he wanted me to check to help eventually diagnose my original IP with a snapped main shaft. so in saying that, these guys seem to know their stuff.



If the compression is good things should be fine.
Another thing to check is the blowby. With the engine at idle speed remove the oil fill cap and observe any smoke/vapor coming out.
This should be minimal and with just a little rpm added it should go away totally.

Oil pressure should be about 20 PSI hot at idle using 15-40 oil and run down the road at about 40 PSI.


My oil pressure is running at approx 50PSI at road sppeds and approx 30-35PSI at idle. So that should seem to be ok and within range.


With any reasonable care these engines will run a long time with minimal issue.

The IP and the injectors are good for about 100K miles even with good clean fuel.

The cleaner the fuel the longer they last.

The factory fuel filter is a very poor excuse for a filter and a good racor with a 2 micron filter is far better.

Hope this helps

Robyn

The fuel should be clean going into the IP as I have 2 large aftermarket filters between the tank and IP.

I want to also take the pan off to check the main webbings too.... where do I look for cracks and how hard are they to find???

Ohh yeah, forgot to mention that the reason I'm doing all this is cause I got a 6.5 turbo kit sitting on the floor at a mates place that's working in NY for a year or 2, so I'd like to have the truck running nice and healthy for when it gets here!!! I've recently found out some history to the engine from a previous mechanic that used to service it.... seems it's got the bigger 6.5 heads on it. How can I determine if it has 6.2 or 6.5 heads?? I'm lead to beleive that the 6.2 engines need the bigger 6.5 heads if running a 6.5 turbo.... is this correct???

Thanks for all the advice Robyn... much appreciated

[DieselCrawler]

Web cracks: Once you pull the oil pan, look for cracks parralell to the main berring cap bolts... mine was cracked in 3 or 4 places, I still stuck new head gaskets on it, bolted on the turbo kit I found on Ebay, and ran the dog turds out of it... that was 4 years ago, I've put 25K hard miles on it, and it's still holdin' together...

If I recall correctly, mine was cracked at the bolts closest to the crank, as in, the in-board bolts, only one (maybe) was the outboard bolt. Some cracks were only 3/4" long, others 2" or so...

I'm lucky enough to have 3 spare motors in the garage, so my theory is "run it till it blows!"

Good luck with your motor issues... hope you get them sorted out soon...

[DmaxMaverick]

If I do come across one that is lower than 300PSI, does this mean rebuild time??? Is there any other remedy.... new rings maybe??......

Not necessarily. The compression test should be done on a hot engine. If you can't do it hot, then the results can be somewhat misleading. Most often, the test results will be lower than would be on a hot engine. More important than actual pressure, is consistency. All the cylinders should be within 15% of each other. On a cold engine, rearward cylinders will normally be lower than the front. # 7 and 8 may even show to be below acceptable.

On a cold engine, it is normal to see 250 PSI, with a gradual decline of cylinders toward the rear. When you do the test, remove all the glow plugs at once, then allow up to 10 puffs for each cylinder test (normally only 6 puffs on a hot engine). What you are looking for is a trend, and not really a specific target pressure. If you have one or two cylinders lagging, it should be pretty obvious.

On a cold engine, a cylinder leakdown test is much more effective.

[brighty]

OK, so here are some pics of my truck & engine.... its a 60 Series Landruiser, chopped down into an Extracab with custom made tray etc etc...

http://i7.photobucket.com/albums/y293/brighty4wd/DSC00168.jpg
http://i7.photobucket.com/albums/y293/brighty4wd/DSC04855.jpg

http://i7.photobucket.com/albums/y293/brighty4wd/DSC04852.jpg
http://i7.photobucket.com/albums/y293/brighty4wd/DSC04853.jpg
http://i7.photobucket.com/albums/y293/brighty4wd/DSC04854.jpg

And this is when I was near a mates place up the coast.... she decided to have a rest half way down the track..... due to driver error...HAHA.
http://i7.photobucket.com/albums/y293/brighty4wd/DSC00029.jpg

[jogl]

That is a sweet little rig. What is a 6.2 doing in a Toy? That is a transplant, right?

I love that snorkle, I have to get a couple of those for my W250 and my Rally van, am always worried about sucking up dust out on the farm.

Good Day,
JP.

[brighty]

That is a sweet little rig. What is a 6.2 doing in a Toy? That is a transplant, right?

I love that snorkle, I have to get a couple of those for my W250 and my Rally van, am always worried about sucking up dust out on the farm.

Good Day,
JP.

Yeah, has been transplanted.... I found this engine to be great for my toy for the low down torque when out in the bush... it's amazing what it'll just idle over in low range 1st gear!!!

If you're after a snorkel similar... check out the ARB range of products, they do most style of trucks here in Australia but not too sure about your models over there.

Ben.

[BigGun J]

Looks good. I am nearly finished with my 6.2 transplant into my 1985 FJ60. I will be running a 700R4 auto, advanced adapter to the splitcase. Cant wait to get it going.

Jim