ID marks

I just got into an '84 k30 diesel. It was parked (inside) 30 years ago yet fired right up. Except the oil pressure gauge pegs high so that needs attention. Any known issues or likely culprits to check?

Also, it's some kind of mongrel as it has a turbo but no idea which. Any suggestions for ID marks to look for? I'll try to get pix soon but meanwhile any clues would be much appreciated.

First thing verify with mechanical gauge.

fast 99 said:

First thing verify with mechanical gauge.

Click to expand...

Yep,and if confirmed high my money says oil pressure relief valve in the oil pump is stuck.

Thanks guys. Two followup points.

1. The oil pump and relief valve are presumably in the sump so I'd pull the pan? (I ordered a service manual but it's not here yet.)

2. After I rustle up a gauge, any hint/clue where to plug in?

Thanks again!

Yes you pull the pan. The gauge screws in,in place of where your existing oil pressure sender is screwed in

Ricko1966 said:

Yes you pull the pan. The gauge screws in,in place of where your existing oil pressure sender is screwed in

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Great. Sounds straightforward. All I need to do is find it. (Sure will help when the manual arrives.)

I got some pix today under the hood of the 84 k30 diesel with turbo. No documentation, just a 30 year old ad clipping stating it had "new 6.2 turbo, trans. & transfer case" at the time. No idea if "new" meant he (next to last owner) rebuild what he had or completely swapped out power train and if latter then were those rebuilt or what. So any tells, distinguishing marks etc to ID what exactly is under this hood could greatly help with TLC going forward. Is it a Banks turbo conversion? Was a later GM 6.5 turbo somehow mated to the original 6.2? I'm keen to sort out what I'm starting with.

...There is this sticker on the air filter housing but that company seems to have vaporized a quarter century ago.

Dang! Haynes Repair Manual doesn't cover diesel. Neither does Kevin Whipps' restoration book. Guess I'll return those and try to find something else. Meanwhile, maybe next week I can tear into it and try puzzling things out.

Followup: the oil pressure sender was bad. Bench testing with air compressor tool pressure and an ohm meter showed that it "opened up" at low pressure, resulting in pegged dash gauge. Replaced sender and dash needle now comparable to mechanical pressure gauge.

I'm working through a list of issues you'd expect with a 40 year old truck that's been mothballed the last three decades. It has good bones so I'm doubling down on maintenance. I'm optimistic it can be a reliable primary vehicle. I'm a full time RVer and this truck is to carry a vintage truck camper that I've also been restoring.

Another clue? Noticed some fancy ID marks on the passenger side exhaust manifold while replacing motor mounts.

As part of its prior turbo mod both manifolds were obviously replumbed from stock dual exhaust to a combined input to the turbocharger. Thus custom exhaust manifolds would've been part of the install. So...

Does anyone recognize these markings?

I'm not super familiar with these things and it's hard to make them out. But I know Banks made their "Sidewinder" kit for those trucks. Could be that?

@Turbo4whl probably knows something here. Or @Blue Ox

There were a few turbo kit makers in the day. That one is not a Banks or ATS, I suspect you're going to be doing some internet research.

The early oil pressure senders were prone to shorting. I was driving in to Brooklyn once when the truck was new and looked down to see the gauge pegged.

Not a happy thing im that neighborhood. But I called in when I got to my destination and was advised that if the regulator was stuck it would have blown the filter off the engine. True that. Put a new sender on it and it's been fine ever since.

Remember, it's an 80 lb sender, not a 60 like a gasser.

Blue Ox said:

There were a few turbo kit makers in the day. That one is not a Banks or ATS, I suspect you're going to be doing some internet research.

The early oil pressure senders were prone to shorting. I was driving in to Brooklyn once when the truck was new and looked down to see the gauge pegged.

Not a happy thing im that neighborhood. But I called in when I got to my destination and was advised that if the regulator was stuck it would have blown the filter off the engine. True that. Put a new sender on it and it's been fine ever since.

Remember, it's an 80 lb sender, not a 60 like a gasser.

Click to expand...

Thanks. It runs good so I'll drive it but monitoring early and often. The vehicle had been stolen and recovered around 95 and garaged since then. I bought it from the widow of my buddy who passed away several years ago. He got flustered sorting it out since it was partially stripped when found. The dash had issues I've mostly sorted out. The cluster has diesel fuel gauge but 60psi oil pressure gauge. I put a new 60psi sender in and checked calibration with shop air and it's within a few percent. The odometer was missing so I got a 6 digit speedo from CJ Pony Parts and that's reading close enough. Stem to stern I've dumped cash into wheels and brakes, driveline seals, suspension joints, most of the steering system, motor mounts. Now I'm sorting out the HVAC and seeing about R12 to R134a conversion. It may be a money pit yet but at this point it seems like a good problem to have.