Bought an old S15 Jimmy...

[crashz]

The truck is and 89 GMC S15 (the little one) Jimmy. 4.3 V6, unknown mileage but believed to be over 150,000 miles. Automatic transmission, 4x4 and loaded with options. I picked it up as a winter car from my father, but it has been sitting for a couple of years. As far as I know, it runs pretty good (fast idle is stuck, so I have to chase that down this weekend) but probably hasn't had any maintenance in a long time.

My thoughs are this:
1 - change the oil and filter with some HDEO and ARX
2 - do a drain and fill on the transmission with a filter change. At the same time drain and fill the transfer case and diffs.
3 - lube all grease fittings.
4 - pull the wheels and check the brakes.
5 - drain and flush the cooling system.

Is there anything I missed? Anything I should be aware of? I would like to get it road worhty again and start driving it in the next month or so. Any tips or advice would be greatly appreciated!

 

[davidfarming]

I have a 89 S-10 Blazer (2wd) with the 4.3. I have had it since new. Very reliable. Only other suggestion would be to check condition of the plugs/wires and the belt and hoses. I also think it is the nature of this beast to blow blue smoke when first started up. It has done this since about 80k, it now has 155k. It has been better since High Milage oil.

 

[MAJA]

I think I would do the ARX clean and rinse with regular dino oil. Then switch to a Delo or Delvac diesel detergent oil, probably in the 15W-40 range.

 

[Jim Spahr]

Crash, while you are doing the front brakes, be sure to check the front wheel bearings and grease them. David F, there is an upgraded 4.3 valve seal made from Vitron or Viton(sp?) which is to correct the 'blue smoke on start up' problem. The stock stem seals leak down and allow oil into cylinder. When you start engine, this leakage causes blue smoke until it is burned off. The seals are relatively inexpensive. The labor to replace them is not, unless you can DIY.

 

[crashz]

Thanks guys!

Jim - the front wheel bearings are a unit bearing and hub (4x4). How can they be greased? Is there a method that applies to all unit bearings? If so, I'd like to service the front wheel bearings in my F150 too. I've always been under the impression that these unit bearings need to be replaced anytime there is wear suspected.

 

[Jim Spahr]

I was thinking they were 2WD when I wrote that.

 

[Russ]

How about a full tune-up (plugs, wires, dist. cap + rotor, air, and especially fuel filters, PCV valve, etc)?

 

[crashz]

Well - I went to my fathers and got it running. Cranked it over and it fired right up! Even with crappy 4 year old gas in the tank! It looks like it aged 20 years though. I should have done this two years ago. Rust is bubbling up in the wheel wells and the rockers are pretty bad. Little things like a tail light, and interior peices need attention. It will be a work in progress. I'll continue to work on it here and there and get it running well.

The service engine light is on (not surprisely), is there a way to check the codes on these older FI vehicles?

 

[MAJA]

A person used to be able to bend a paperclip, or wire, to press into two of the "underdash computer port" slots, in these older, pre OBD-II vehicles. I dont remember which connections though. I think the older code readers for this vehicle essentially did the same thing, you just didnt have to know the appropriate ports for the wire.

What you did was put the wire in, and turn the ignition on. Then you counted the flashes of the "check engine". For example, 5 flashes followed by 7 flashes was a code "57". It would pause, and give you the next code, until it repeats itself. Of course, you needed a listing of the code numbers to make a fix. I would suggest a shop manual, such as Chiltons or Haynes. I think Haynes is better in my opinion, and has the codes listed.

 

[MAJA]

To add to that, I think the Haynes manual actually tells you which ports you have to bridge across with the wire, or paperclip. Each port either has a number or a letter, if I remember right. Maybe someone can add to this?

 

[liquidballbearing]

You are most definitely correct MAJA as I have the 1982-1993 Chevy/GMC S-10/S-15 Haynes manual in my hand--one of the best investments I have ever made. Very reliable information often with "short cuts" or helpful information not given in some manuals. I have used a paperclip to check codes several times before finding a $2 tool that does the same thing.

 

[crashz]

Thanks guys for all the useful insight! I'll be going to the parts store today to return a transmission filter so I'll pick up the manual while I'm there.

One more quick question (which may be explained inthe manual). The truck has a digeital dash that intermitantly displays the speed and mileage. Has anyone ever repaired one of these?

 

[QuadDriver]

quote:

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Originally posted by crashz:
The truck is and 89 GMC S15 (the little one) Jimmy. 4.3 V6, unknown mileage but believed to be over 150,000 miles. Automatic transmission, 4x4 and loaded with options. I picked it up as a winter car from my father, but it has been sitting for a couple of years. As far as I know, it runs pretty good (fast idle is stuck, so I have to chase that down this weekend) but probably hasn't had any maintenance in a long time.

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Im sorry to hear that....(forgive, but GMs S/T trucks are from satan.)

There is no 'fast idle', you have 1 of 3 likely causes (with by no means a small number of unlikely ones)

1. IACM is sticking, unhooked, gummed up or otherwise bad. This is the 4 wire dohickey on the rear left corner of the TBI unit as you face the vehicle. Screws out, screws in, you only have to set initial plunger depth when you buy one.
2. Vacuum leak. These hideous little creations are famous for ditching intake gaskets - but usually only on the coolant crossovers, but after some rusty years who knows. Also look at the TBI/intake mani gasket.
3. Bad, missing, broken etc AC compressor connector with the HVAC switch set to something that uses AC (MAx, Norm, Bi-, Def)

As for the digi dash...they are pretty much non-repairable, just replacable. But if you mean by intermittently displaying speed, then I would suspect a bad speedo head unit if your year is one where the VSS is on the speedo.

 

[crashz]

Thanks Quad driver. I seem to remember being able to barely see the outline of the speedo numbers, but the back light or what ever does not always work. I want to tear into it and see if there is just a loose wire or connection, but as it it now, everthing else works right. I'll probably just mess it up more.

When I fired it up, the idle seemed normal and the digital tach read about 800 rpm in Park. Seems OK

The truck will need some serious TLC. When I checked the radiator, it looked empty. I'm begining to reconsider.