A couple weeks ago I noticed my one battery wasn't working, so I took it to my mechanic, they swapped it out for a new batter, and put new connections on it. Now what's happening is my glow plugs arn't working, andmy fuel gauge is going all over the place. In order to get it to even start, I have to park it in my heated garage, and plug the block heater in for atleast 20 minutes. Could this be a bad ground problem? Is there a short somewhere? I wasn't having any serious problems like this until the new battery was put in. Should I try disconnetion the new battery to see if the new battery is the problem? Any help would be greatly appreciated.

Swap out the battery you put in......go from there.

You're starting your truck on one battery, in the winter??

Welcome to the diesel place. It would help if you could do the check list
here http://www.dieselplace.com/forum/showthread.php?t=42248
and post the results

Helps us help you and as a great bonus you will learn a lot.

You should always replace batteries as a set. I would double check the connections too.

No, the truck has been in the garage for the past two weeks. I just tried each battery, and the new one works great. The old one is very weak. With just the new one connected it seems to fire perfectly. I'll have to wait till tommorow when it's cold again, to see if it the glow plugs are gonna work properly, etc. I left it outside one night and with the block heater plugged in for 5 hours it wouldn't start. Then again, it has been -45 Celcius at night here. Before, when both batteries were plugged in, the glow plug light would flicker on and off about 6 times before it would permenantly stay off. It seems to only come on once, then go off permenantly (the way it's suppost to) now, with just the new battery connected. Maybe the old battery is shorting everything out? Could that cause serious problems?

Yup nerver mix batteries (that is never) LOL

In a parallel battery circuit (what we have) the batteries will equalize. The problem is that the *bad* battery has a bad cell (or more) and will just suck the life out of the new battery till they're both dead - But equal.
I'd disconnect the bad battery --- Like now!

No, the truck has been in the garage for the past two weeks. I just tried each battery, and the new one works great. The old one is very weak. With just the new one connected it seems to fire perfectly. I'll have to wait till tommorow when it's cold again, to see if it the glow plugs are gonna work properly, etc. I left it outside one night and with the block heater plugged in for 5 hours it wouldn't start. Then again, it has been -45 Celcius at night here. Before, when both batteries were plugged in, the glow plug light would flicker on and off about 6 times before it would permenantly stay off. It seems to only come on once, then go off permenantly (the way it's suppost to) now, with just the new battery connected. Maybe the old battery is shorting everything out? Could that cause serious problems?
Replace the other battery with the same as the first. With one bad battery it can cause problems.

Thanks for the help guys. I'll get a new battery tommorow, and hopefully that works. My fuel gauage is still going all over the place. Anyone have any ideas on what it could be? The glow plug's seem to be working fine now, but who knows. Maybe there's a bad ground somewhere still?

fuel gauge works on a ground completion. usually got a loose, or coroded wire wire from frame to sending unit. could be a bad contact in the gauge cluster, but usually you see more than the fuel gauge screwing up with that

If it wasn't bouncing before the battery swap, then you need to check
all the battery cables and connections - and just cause it looks good
on the outside, doesn't mean it's not corroded under the insulation.

Got another new battery, and checked the grounds on both batteries, they both seem to be fine. No corrosion on the connections, etc etc. My glow plugs are flickering on and off 5-6 times again. Does everyone agree that there is a ground issue somewhere? Could it be the glow plug controller?

Maybe its the ignition switch...

Got another new battery, and checked the grounds on both batteries, they both seem to be fine. No corrosion on the connections, etc etc. My glow plugs are flickering on and off 5-6 times again. Does everyone agree that there is a ground issue somewhere? Could it be the glow plug controller?

Still could be a ground issue seen as it started with a battery replacement. By chance was the first battery on the passenger side? There is a small ground that goes to the fender on that side, I would check to see if that broke off or has a bad connection. Take it off and clean the fender and connector good with sand paper or something (should be shiny clean) The bigger part of that ground goes to the intake clean it the same way while you are at it. That small one could be critical for the glow plug controller, even though the controller is mounted on the intake. It would be easily broken and maybe causing the controller to act up.

Alright, i'll try that in a bit, after the truck stops smoking. Changed the fuel filter today, went for a little drive, come back, there's smoking coming from the hood. So I pop the hood, and all i can smell is gas. The filter went in perfectly and it got screwed on tight, and no, it wasn't cross threaded. Anyone wanna buy this piece of crap? Had the truck 3 weeks, and i'm already sick of it. So, let's see...the truck won't start, my gauge's are going crazy, and the bitch is leaking fuel somewhere. G-R-E-A-T.

k ill buy it;) how much and you deliver?

You never gave sig specs......year, make, model, F-S engine, miles, mods?

97, 6.5 turbo diesel. 400,000 km on everything except new motor. new motor has roughly180,000 km's on it. it's bone stock except for cat and muffler cut out. just straight through exhaust. finally got the fuel leak problem fixed, still have problems with the fuel gauge and the glow plugs. i'm gonna check all the grounds again tommorow. could someone tell me where all of them are? i know there's the one on that bolts the metal on the passenger side right by the battery and then the two that go from each battery to the motor. what other ones are there?

Alright, i'll try that in a bit, after the truck stops smoking. Changed the fuel filter today, went for a little drive, come back, there's smoking coming from the hood. So I pop the hood, and all i can smell is gas. The filter went in perfectly and it got screwed on tight, and no, it wasn't cross threaded. Anyone wanna buy this piece of crap? Had the truck 3 weeks, and i'm already sick of it. So, let's see...the truck won't start, my gauge's are going crazy, and the bitch is leaking fuel somewhere. G-R-E-A-T.

Did you make sure the filter went down all the way? You have to line up the tabs on the top of the filter housing with the holes in the bottom of the filter. There is a big tab in the front (lines up with a big tab on the filter) and there are little tabs the rest of the way around. Also there is a metal ring and a rubber sealing ring that have to be installed. Also make sure the old rings came off with the old filter. I just changed my filter the day before thanksgiving (for the first time since i owned this truck) and it took me a little while to get it all right but it is done finally. It can be a bit of a challenge. Just check on it, i bet it isnt seated right. Its real easy to make that mistake if you havnt changed the filter before.

Here is everything you should need to know about 6.5 grounds. Very important!!!


http://www.dieselplace.com/forum/showthread.php?t=163087


http://www.dieselplace.com/forum/showthread.php?t=157085

Well, I took the truck to a diesel shop, they put all new glow plugs in again and a new controller and it seems to running fine now. As far the fuel gauge problems, and the other problems, the guy thinks it's a bad ground somewhere. The guy said when I replaced the one battery, I should have replaced the other also. What happened is the one battery wasn't enough power for the glow plugs to cycle properly, so they basically stayed on and burnt on. With two new batteries, new glow plugs, and a new controller it runs good now. Hopefully figure out the other stuff soon also, but it's not a big deal. Atleast the truck actually runs now, and I don't have to worry about it not starting. Also, with 180,000 km on the motor, and 400,000 km on the tranny, and the rest of the drive train, should I even look at chipping it? I would like to see some more power, but just curious as to what's the easiest way. I've got 400 WHP civic (aka vette killer), and this truck just isn't the power that i'm used to. I have a manual boost control sitting around, could I just simply turn the boost up a bit? Or would a chip be the best way?

Have a look here a Heath Diesel. I don't know the year of your truck so find the year and then find the kit you want or how much you have to spend.
Glad to see your getting the bugs out.


http://www.heathdiesel.com/T/Chevy-GM/Chevy-9495/Performance-Combos/

Just wanna say thanks to helping for helping me out. One last thing. Going from 2nd to 3rd gear my tranny seems to slip. It doesn't do it in all gears, Just from 2nd to 3rd, maybe 3rd to 4th. Can't remember 100% which gear's it is. I've briefly talked to a mechanic about it, and he told me something about the synchro's need to be tightened? Anyone agree, or do I have a more serious problem. I've got about $800 Canadian that I can use on the truck for whatever. If I have to get the tranny rebuilt, I will. If not, the money will be doing into a chip.

I don't see more power doing your trans any good. I'd do the transmission first.

X2 if the tranny has 400,000 it is probably more than an adjustment.

Just wanna say thanks to helping for helping me out. One last thing. Going from 2nd to 3rd gear my tranny seems to slip. It doesn't do it in all gears, Just from 2nd to 3rd, maybe 3rd to 4th. Can't remember 100% which gear's it is. I've briefly talked to a mechanic about it, and he told me something about the synchro's need to be tightened? Anyone agree, or do I have a more serious problem. I've got about $800 Canadian that I can use on the truck for whatever. If I have to get the tranny rebuilt, I will. If not, the money will be doing into a chip.


Syncros dont make a slip. And there isnt an adjustment you pull the old out and put in new. Bad syncros will allow it to grind on a shift. To heavy of oil will make it hard fo the syncros to do there job and hard to shift. These manual trans take a special oil from the dealer. A clutch can slip with a higher load

If its a manual trans and it is slipping then its the clutch not the trans. It could be out of adjustment but likely the clutch is worn.

It's an automatic, and it doesn't do it on all gears. Should I try different tranny oil? I just use standard ATF. The truck hauled a 32 Foot travel trailer for one summer, the rest of the time i've owned the truck, not much heavy loads. It hasn't seen a trailer tow in atleast a year. Take it to a tranny shop and get them to check it? Just need some ideas on where to start. If I don't need to rebuild the tranny, i'd rather not.

If its an auto and its slipping it needs to be rebuilt especially with that many miles on it.

Anyone have an estimate on how much? Also, would I bet better off to get a new exhaust or get a chip. I know that I should get both, but money doesn't grow on the tree in my backyard. What size of exhaust is on the 97 gmc 6.5 diesel's? It looks like 2.5 inch pipe. What I was thinking was...getting new manifold and cross over piece and then just run an open dump out the side on the front. Get a better flowing manifold, turn the boost up and just run open dump just behind the passenger side front tire. Any ideas?

Anyone have an estimate on how much? Also, would I bet better off to get a new exhaust or get a chip. I know that I should get both, but money doesn't grow on the tree in my backyard. What size of exhaust is on the 97 gmc 6.5 diesel's? It looks like 2.5 inch pipe. What I was thinking was...getting new manifold and cross over piece and then just run an open dump out the side on the front. Get a better flowing manifold, turn the boost up and just run open dump just behind the passenger side front tire. Any ideas?


Trans will probably be around 1800 US dollars. You need the exhaust before the chip. Stock size is 2 7/8". To my knowledge there arent any aftermarket/better flowing manifolds for the 6.5s. Turning up the boost will do more harm than good without adding more fuel which you cannot do without a performance computer.

I'd be better off finding a used tranny that doesn't have many km's on it then. So if i go a new cross-over piece in 3-4" and then just made my own dump, that would work. Anyone ever done it? If I did new cross-over and open dump, would I be able to see a big difference?

I'd be better off finding a used tranny that doesn't have many km's on it then. So if i go a new cross-over piece in 3-4" and then just made my own dump, that would work. Anyone ever done it? If I did new cross-over and open dump, would I be able to see a big difference?


Biggest crossover that they make that i know of is i believe 2.5". That's really more than enough for a crossover pipe as it only carries the exhaust for 4 cylinders. You should notice a difference with a 4" exhaust but im not sure youd notice a change in the crossover. As for the transmission i wouldnt get a used one myself altho a used one would probably be ok.

Well I need a new crossover piece anyways. For now I'm just gonna run open dump to see how it is. As far as the tranny goes, I was just told that it is probabally just because of the filter. When my Father had the truck, I don't think he EVER changed it. Monday, I'm pulling off the filter and changing the oil, see how that works. Hopefully it fixes the slipping from 2nd to 3rd.

As for the transmission i wouldnt get a used one myself altho a used one would probably be ok.

OR - Buy a used trans - Rebuild IT - Quick swap, eliminating the down time while your's is being rebuilt.
You're going to be just wasting a filter & fluid & all the fun of changing it on the trans you have now. The damage was done by not changing the filter before it started slipping. Classic case of locking up the barn after the horses have split.

What tranny is in the 6.5's then? Have to start searching for a used one. If I could pick one up for under $1000 canadian, that would be perfect. Anything else I should be worried about going with 400,000 km's? Like driveshaft, or rearend or something.

I would check diff. for metal shavings, condition of u-joints on driveshaft,... etc.

240,000 miles (not sure what that is in kms) on my auto trans (4L80E is what is used) and never had its fluid and filter changed. Kind of afraid to at this point...new fluid acts sorta like a solvent and can free up any gummed up fluid or anything in the trans and possibly clog up somewhere in the valve body and cause all kinds of problems. As stated i would check ujoint and rearend. I probably need to do the same. I am pretty sure that the positrac portion of my rearend is not working anymore. Nothing is surprising with this many miles tho...

Well one of my Father's friends has a 6.5, and he was having the same sort of problem. He changed the filter and fluid and it stopped slipping. Not sure if it just bunged up with crap, but I may as well give it a shot. If it works, well I just saved myself a lot of money.

4000000 Km = about 250000 miles, tranny COULD need a rebuild -
but if you are having electrical issues, that could be causing your
transmission trouble - I'd get that checked out first, before doing
anything to the transmission

Okay, well first off, how could electrical problems be causing the slipping problem. Also, wouldn't it cause it to slip in all gears? I forgot to mention, sometimes when I let off the throttle so it can shift, then get back into the throttle, it seems gutless, and smokes a lot.

At work I had one of the trans come in that would fall out of gear at 60. Turned out that any electrical load grounding through the body and the ecm would see a vss reading of 0mph. So a 60 mph the ecm was shifting the trans back to 1st. That truck had a bad body ground.
That not to say that is your problem but If it were that easy would you want to buy a trans. The man that owned that truck was thrilled for a small problem.

Well i'm sure there's a bad ground somewhere. A bad ground would cause the fuel gauge issue, and some other minor electrical issues, but it might be more also. I'm currently on disability, and just bending over puts me in a lot of back pain. Changing the fuel filter nearly killed me. I'll have to try and get all the ground's checked soon though. I was told the problem was in the cluster somewhere, but I think it's something else. If the only electrical problem I was having, was the fuel gauge issue, then yes, it would be somewhere in the cluster. I highly doubt my transmission issues are electrical related. The truck has been in our family since it had 180,000 km's on it, and it has never seen a tranny oil/filter change. I'll have to try that, and hopefully that's the problem. If not, just have to save up some money, take it easy on the truck for a while, and get it rebuild when I have the cash.

im curious about what we are working on, lol

Went for a beer with a buddy tonight, went to start the truck, damn glow plug light is flickering on and off again. If all the glow plugs are burnt again, i'm gonna shove this truck up the mechanics ass. Or drive it till it starts on fire, and watch the prick burn.

Went for a beer with a buddy tonight, went to start the truck, damn glow plug light is flickering on and off again. If all the glow plugs are burnt again, i'm gonna shove this truck up the mechanics ass. Or drive it till it starts on fire, and watch the prick burn.
Just how many beers did you have?:D

Only one. If I have anymore, I don't drive. Find out tommorow if she doesn't start or not. If she doesn't, push her into the garage for few hours, get her started, then bag the shit out of it till she blows.

Only one. If I have anymore, I don't drive

Good man! I wish everyone thought like you do (my wife is out there driving with those jerks).

then bag the shit out of it till she blows.

BAD idea :)
The Glow Plug Light (WTS) is connected directly to the output side of left bank of the controller -- At least it is on my '95, maybe others (?). Can't tell which year your's is, but it would help if you would FILL OUT YOUR SIGNATURE (http://www.dieselplace.com/forum/profile.php?do=editsignature). I have access to wiring diagrams to just about everything, but just don't know which one goes with your's...

The WTS flashing would indicate one of a couple of problems, but I can't see that the glow plugs being burned out would be any of them (been wrong b4 though).
I believe you have a loose connection either at the INPUT side of the controller (smaller wires). A loose connection at the ECM module (yellow wire on a '95). A chaffed, or chewed up, or pinched, wire going to the controller (again the smaller wires). Or the controller isn't grounded well.
Personally, I'd start with the ground. Make sure that the controller's base is making good contact with ground.

All new glow plugs and controller installed a week ago. The guy is suppost to be a very good diesel mechanic, so i'm gonna take a wild guess and say that he did check ALL the wires going to the controller before replacing it. Truck did start fine this morning, however, after it started the glow plug light did go on and off a few times. As far as drinking, a really good friend of mine which I grew up with, died in a car crash because he was drinking. So therfore, if I have anymore than one beer, I do not drive. Doesn't matter where I am. Hopefully next week, after christmas, I can get the truck in and get them to check all the grounds on the truck and see if there's a bad ground somewhere. Tranny issues are still unknown. Haven't got around to changing the oil and filter, however, I checked the rear diff, and it was very low on fluid (practically empty). Could that be causing the slipping by any chance?