Did my mechanic screw up? GMC Savannah still dying after $3300 in repairs

Looking for some advice about how to deal with my mechanic and some repairs. I have a 98 GMC Savannah with a diesel engine that I use once a week during the summer to make deliveries. Last fall, one of the batteries died. It took us a bit to find the frame battery, but we did and after some tinkering, my husband replaced the battery. The van ran fine all spring – we probably drove it 5 times, and then, on one trip, the van died at an intersection while my husband was driving. He said it sputtered and then a minute or two later died and he couldn’t get it restarted – and that the voltage meter was reading low. So we had it towed to our mechanic. I mentioned the recently replaced battery, they said that was the problem – that the bolts had been stripped and they would go ahead and replace the posts, etc. I asked if they were sure it wasn’t something electrical draining the new battery – they said nope, my husband had definitely botched the job. So they fix it, and when they’re test driving it, the tech goes to park it, the engine surges, the tech turns off the engine and then can’t get it started again. They said it had codes indicating that there was a problem with the fuel injector. They said it was burned out and needed to be replaced – and that it was probably caused by running the van on a bad battery. So we told them to replace it. By this time, 3 weeks have gone by, and we have a bill for $3300. They test it, we pick it up, and on the way home, the van dies at an intersection. We have it towed back to the mechanic, and they tell me that it had a weird electrical problem and they’re looking into it. I ask if gave them any codes. They told me that it was giving a code for the fuel injector again, but that clearly wasn’t the problem. After another week, they said that the fuse box had its rain shields removed and was completely corroded and that it would need to be reconditioned or replaced with a used one because it’s no longer in production. They said at this point, it was all labor and it could cost a couple hundred or a couple thousand depending on how long it takes.

What do I do? They’ve had the van for a month and we’ve paid them $3300 and it seems like the problem is unsolved. Does what they’re telling me seem plausible? That they fixed the battery and found the injector problem which then in turn uncovered the electrical problem? It seems like the electrical was always the problem and I paid for a fuel injector that I didn’t need. Should I try to get them to cover the cost of the repair? Is that unreasonable?

Sorry if this was a little incoherent – just need a little advice. Thanks in advance.

For replacing a battery and one injector, $3300 seems a little steep to me. They must have done other stuff, or significant diagnostic time. If the fuse box is corroded, it will have to be replaced or fixed somehow or another. Replacement is the best method if you can find a NOS or used one from a junkyard. The electrical system has to be working to have a reliable car, that’s 100% certain.

But that might not be the entire problem. As I read your post my first thought was a problematic injector pump. Has that been tested? Also has all the old fuel been drained out and replaced with fresh yet?

Sorry! It was the injector pump that they replaced. We had just filled up the tank before the problems started…

They have no idea what they’re doing , just throwing parts at it . Take it to a real mechanic .

I think they may have found the problem with the electrical stuff. Once on a VW diesel a friend of mine found a bad connection on the electrical harness which would have been expensive to replace. He drilled out the connector area for the one wire and ran a wire through the hole. Problem solved. His bad connection was for the glow plugs.

I’m afraid that I will be of little use on this one as I’m not familiar with domestic diesels. My diesel experience is mostly with VWs. Still, principles are the same.
Seeing as how this problem happened right after filling up the tank has the possibility of fuel contamination been considered?

If the fuel is tainted and what I would have done (assuming it was not) would be to take a decent sized fuel sample before replacing the injection pump.

If there is an electrical issue with wiring what about the possibility of a fuel shut off on the injection pump becoming inoperative due to a lack of electrical power caused by a corroded connection?

Sorry I’m not of much help here but with random dying and no starts I would suspect fuel contamination or an electrical issue shutting off the fuel.

If I was in this situation and the tech told me that the low battery charge condition probably caused damage to the fuel injector, that would have been my cue to run, run real fast to another shop. Like Tommy used say about wrong repair advice…bo-oh-oh-gus.

A friend of mine had trouble with his Dodge diesel one time where it would just die and he couldn’t get it started, then it would start. After looking over the service manual diagrams I thought we would see what happens when we swapped the fuel pump relay. That fixed the issue.

I have to think that the amount of money you have been charged for this is getting close to the value of the vehicle. How much more can you take? Like you, I suspect the problem was really due to some sort of electrical problem, a relay possibly. I think it is time to have a one on one with the shop owner and ask him what is going on and how can you be expected to pay a bill like this and still have a vehicle that isn’t running right.

Yes, the low battery causing damage is totally bogus.

Thanks for your input, everyone. I think they’ve found the problem with the fuse box, too – but I really, really don’t want to pay for it – which sounds ridiculous, I know – but I’ve already given them so much time and money for what seems to be an unfixed problem. It’s hard to call their bluff when I know zero about diesel engines – and this garage has done other (expensive. seriously.) fixes on this van in the past that have worked fine, so I trusted them. I will talk to the owner and see what we can work out (for the other repairs in the saga, I was talking to the tech guy – for this latest bit, they’ve had me talk to the kid behind the counter, which is awesome). And then find a new mechanic. Agh.

You are living the downside to diesels… they are expensive to fix. Sounds like they didn’t really diagnose the problem, just took a stab at it with your checkbook.

The whole point of hiring a mechanic is so you don’t have to know anything about diesels, or vans for that matter. You are paying them because they should know about diesels and vans. Don’t criticize yourself for that.

Maybe find a new mechanic and consider it lesson learned.

It seems that you have been a good customer with them in the past and be sure to make that known. Hopefully they will work with you if they want to keep your business. If they don’t budge then you can tell them that “they got your money this time” but they won’t be getting anymore, ever. Even good shops can make mistakes now or then, but a real good shop will want to keep you as a happy customer. If you need to find a new shop then maybe a search on the Mechanics Files (see header above) on this web site may help you locate one.

If it was the injection pump rather than a single fuel injector they replaced, the price seems more in line. Injection pump replacement is expensive. That part seems to be the weak point in diesel engines from what I can tell. Not just your make, but in general. Other than that, diesel engines seem to be pretty tough and reliable.

Re: low battery causing damage is totally bogus

I wouldn’t go quite that far. Low battery voltage can cause damage to some electrical components, especially those which rely on what is called “back emf” to reduce the total current draw. For example the starter motor design relies on back emf, the idea being that the faster it turns, that turning acts like a little voltage generator, so more back emf it provides opposing current flow, so the lower the current draw. If you keep starting your engine using a semi-dead battery it can heat up and damage the starter motor solenoid contacts.