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calpyro
08-23-2007, 22:14
Sorry for the newbie question. I have searched through old posts but I have been unable to find the info.
I am looking at a 6.2l Military Chevy blazer this weekend. Owner says it has new injection pump, and glow plugs and it runs well.
What should I look for in this engine. I understand that it has some quirks, but I am unfamiliar with what I should look for.
Thanks

Robyn
08-24-2007, 07:58
First off

Welcome to TDP :D:D:D:D:D

The little 6.2 is really not all that mysterious.
Its just a V8 engine basically that has all the same systems other than the fuel injection.

If you can supprise the seller with your arrival to take a peek so much the better.
You want to start this engine cold and be able to observe what it does.
If the owner has it all warmed up he may be able to hide something he does not want you to see.

The glow system should stay on for about 15 seconds give or take and the engine should start quickly with a minimum of cranking.
The first few seconds of running can see some blue to white smoke puff up but should clear out quickly and the engine should run smooth after that.
The cold advance and the fast idle will be engaged for about the first 5 minutes and then it will turn off and the engine will idle down.
The normal diesel cackle will be slightly louder when cold until the cold advance shuts off.

Have a look at the usual things such as coolant level, engine oil, tranny oil (Should be red and not yellow or brown and should not smell burn)

Pay close attention to the coolant level in the reservoir as the engine warms up to temp. Look for signs that coolant has been blowing out the overflow hose.
If this is evident you need to find out why. If the top hose gets all hard and swollen like a poisoned puppy after the engine warms there is most likely a head gasket leak or a crack somewhere.

Remove the oil fill cap and take a peek to see how much blowby is coming out. It should be minimal and not huffing a ton of smoke.

A general cruise through to look for the obvious such as oil and coolant leaks.
The engine should spin right over snappily and the starter should not labor to get the engine running.
Check the battery cables for corrosion and overall health.

Take the rig out for the obligatory test drive. The little 6.2 although no rocket ship should get the little truck up to speed with a minimum of effort and without tons of black smoke pouring out the tail pipes.
You should notice a nice little cackle from the engine even while cruising easy. Take note how the tranny shifts too, smooth and crsip with no wild slips during shifts.

Once you are done with the test revisit the underhood area to have another look at the coolant level and anything else that might need looking at.

Be sure to watch the temp gauge and the oil pressure gauge.
Oil pressure should run 40 psi hot down the road and idle at 20 psi this can vary slightly but if you see a big variation from these numbers there may be issues.
The temp should run 180-195 depending on what stats are in the thing.
Any wild numbers on the temp can mean issues too.

Other than these things its just pretty much buisness as usual when buying a used rig.

If you find the seller getting nervous when you ask questions he/she may be hiding somthing and posible trying to cover a bad fault.

If the seller gets pushy you can almost be assured they are trying to get the thing gone quickly before you find out what the straight scoop is.

Have fun be cautious and enjoy.
Best to ya and keep us posted.

Robyn

moondoggie
08-24-2007, 09:13
Good Day!

If you can ascertain for sure it's cold (touch stuff to make sure it wasn't warmed up B4 you got there, like robyn says), a good 6.2 will start in less than 2 seconds of cranking (after a normal glow plug cycle), assuming ambient > 30° or so.

When the engine's at full operating temp, it should start almost quicker than you can hit & release the key. If it does this, there's reasonable odds the compression, batteries, battery connections, & IP are OK.

Other than that, what she said.

Let us know...

Blessings!

calpyro
08-24-2007, 12:49
Great info! I will make a list of your suggestions and give it a go. I will post some pics and results of the test drive.

I saw some posts regarding some engine failures. What are the most common areas to fail?