6.2 good motor? never bought a 6.2 before

[jacobcurtis]

I have never owned a 6.2 but was wondering what to look for when buying one. I am going to look at a 1988 suburban 4x4 with 146k mileage. It looks clean and straight and the guy says it runs good. What should I look for when looking at the motor? Any known problems to look out for.

Thanks

[Rytari]

1St oil leaks... its not new, so i will have those, i it got bad leak, somebody usually cleans engine before selling

heads maybe next issue, blown headgasget/ craked head will bring bubbles to the radiator when engine running, there should be some pressure when you open the cap, but with open cap not any airbubbles alloud to come up.

more bad is when cap is full of grey "foam" then you got oil mixed up w/ water.

rought runnign.. all 6.2 diesels sound littlebit ugly, if it runs too smooth its somehow broken but it should not wibrate much when idling, old ones always shake little, but if your tooths fall off when engine idles, it might had worn injectors etc.

blow by, open oil cap... if it looks air is moving OK - if it seems to having a old train inside, bad

rattling sound belongs usually to it, knocking not... mine once sounded like "Plop Plop plop" from intake, valve or lifter issue then

im not any expert, just have been driven some of those, i just thought my advise is better than nothing...

[Robyn]

FIRST OFF

Welcome to TDP
Glad to have you.

Have the seller leave the rig sit cold overnight and you be the first to start it when you go to look at it.
This will tell you the basic condition of how good it is in terms of the glow plugs, batteries and the IP.
Glow the thing and go for a start, it should "SHOULD" start right up with only a small amount of smoke and then run smooth and settle in fairly quickly to a nice even idle.

If the thing cranks slow and or is tough to get going then it may have some issues.
Look the engine over for the basics such as large oil leaks and or fuel leaks.

The 6.2 is really no different than its gasser counterparts in that it is a 4 stroke V8 engine.

Now once the little creature is running, take it out and warm it to operating temp and see how it performs. These are not a rocket and a big O'l Burb is not going to set the world on fire with a 6.2 up front.

After the temp comes up watch the gauges and pay attention to the oil pressure and the water temp. The temp should stay fairly stable and not bounce high or anything wierd.

The oil pressure should run about 40 at road speeds and idle at about 20 when hot.

Now when you get back from your road test have a look see under the hood and examine the overflow on the radiator/surge bottle and see if there are signs of burping of coolant.
Also check the upper radiator hose, be sure its not as hard as a swollen puppy dog about to pop.

The reason for checking these things is to acertain whether there may be a head gasket or other internal leaks.

If there is it will manifest itself by overpressure in the cooling system and the signs of overflow of coolant on things in the engine bay.

The rest is pretty much autoshop 101.
Look for signs that the thing has most all of its factory equipment still hooked up and running and that things look to have been cared for.

The test drive will allow you to also pay attention to the tranny and how it shifts.
Yank the dip stick on both the engine and the tranny after you shut down for a few minutes.
Make sure the engine oil is either fairly clean (as in just changed) or usually black.
The tranny fluid should be red or something close and not smell burnt.
Many times a high miler will show the tranny oil to be brown to yellow but things still work ok. ( A change in order)

The battery cables on these need to be in good order as well as the batteries.
Look for stuff like the mickey mouse clamp on cable ends and stuff that has been thrashed together to make it go..

Have fun ahnd good luck

Keep us posted and ask any ???????// you feel a need to.

Best
Robyn

[jacobcurtis]

Thanks for the tips guys. From what I am reading blown head gaskets and bad heads are an issue with these 6.2s and I need too look out for this. I will keep you posted on how it goes.