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Thu 2 Aug 2007 17:53

GMC 6.2 V8 diesel - any good? - nick

I'm looking at an '80's Chevrolet with a GMC 6.2 litre V8 diesel fitted. I know the earlier 5.7 diesels had a bad reputation for reliability but does anyone know what the 6.2 was like? There doesn't seem to be a lot of information out there in internetland so I thought I'd try here. It's a non-turbo BTW.
The gearbox is the 4 speed overdrive model, I believe these are pretty good, is that correct?

Thanks.

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Thu 2 Aug 2007 19:19

GMC 6.2 V8 diesel - any good? - Screwloose

nick

It's a basically sound engine with an interesting history. Once GM had dropped the 5.7 in the mid-sixties, the rights were sold to their subsidiary Detroit Diesel-Allison and they had the engine "ruggedized" and stretched to 6220cc [possibly by Ricardos] along with a change from Stanadyne pencil injectors to Bosch. The pump is still a Stanadyne but heavily modified and quite reliable.

When Penske bought Detroit from GM around '87, they had to hand back the rights and GM decided to further develop it for use in some of their 4x4s, pick-ups, minivans [Suburban] and even the Hummer/K-line trucks. There were several UK importers of used units that were a popular swap for Range-Rover V8s - the turbo version could go to about 450bhp.

www.the dieselpage.com is the best place for info on them; but overall, they're a good unit - just never buy one that's been over-heated.

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Thu 2 Aug 2007 20:36

GMC 6.2 V8 diesel - any good? - nick

Screwloose
Many thanks for that, especially the link. This forum never ceases to amaze me!
The engine is in a Caprice station wagon, replacing an earlier 5.7 unit. It's had 2500 mile oil changes (allegedly) so should be in good condition and understressed even with a bit of caravan towing.
If I buy it I'll report back.
It always amazes me that american engines can produce so little bhp from such large displacements but I suppose that's why they are usually so reliable. I've read that a lot of the reliablility issues with the 5.7 were poor fuel and lack of knowledge on the part of the average US mechanic more familiar with petrol V8s, plus a poor design of the tappets which was fixed with a change to a roller tappet design in the 6.2.

Thanks again.

Anyone know anything about the 4 speed autobox?

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Fri 3 Aug 2007 12:43

GMC 6.2 V8 diesel - any good? - Collos25

My brother in law has the same engine in his mobil home I borrowed it for a holiday in France it would have been cheaper to hire a private plane with the fuel it used.

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