6.2L smokes quite a bit

[rodolforuiz]

Hi! I'm new to the forum and rather new to diesel engines. I've always liked diesel engines and finally decided to get one. The truck is a 86 4x4 GMC 2500 with the 6.2L, got the truck for $300. The truck sat for over two years, so far here is what I've done. Initially, starting fluid was a must to start the engine. After changing all the glow plugs and fluid filter with Napa parts, the engines starts right up and does not need the starting fluid anymore. The tank had about 1/4 of a tank of old diesel, so I added 1 gallon of Lucas diesel additive and let truck run on iddle for about 3-4 hours and a second time was iddling till the tank was almost on empty (hope the gauge works properly!!). Then, I changed the thermostat just in case, replaced the fuel filter again and let the truck run on iddle for 3-4 hours using new diesel without the Lucas additive. When I replaced the fuel filter the second time the stuff coming out of the old one came out rather clean a lot better than what I expected, do I need to bring the tank down for cleaning?. The problem I have is the following, when the engine is cold a big cloud of blue smoke comes out of the exhaust and even after several hours of iddling the smokes still there, not as much but it's there. The condesation of the smoke leaves a yellowish color on the ground and the smell is like diesel. When I placed my hand on the exhaust pipe a strong diesel smell is left and the yellowish color is there. The oil pressure seems normal and temperature stays around 180 when it's hot, ambient is been around 70-75 degrees. Someone told me that it could be bad injectors and need replacing, another friend is of the opinion that rings may be stucked or the injector pump is bad. Like I said the engine sounds good to me when iddle and it feels like it has good power when driven around the block. Any suggestions on where to start troubleshooting or should I go ahead and get the engine rebuild. I like the idea of rebuilding it myself, however, I've never rebuild an engine. Any help would be greatly appreciated.

Thanks,
Rodolfo
86 GMC 2500 4x4 6.2L
:confused:

[Robyn]

Cardinal rule #1 ** never use starting fluid on a GM diesel or any other precup (glow Plug) engine.
The ether can and will cause damage to internal parts due to its highly explosive nature.
Your rig after sitting for so long has most likely incured some badly gummed up injectors and even the Injection pump. Best thing is to pull the injector nozzles out and have them gone through at the local diesel repair station aswell as the IP too. Once you get these cleaned and setup properly the little 6.2 should run like a champ.
PLEEEEEEEEEEEEEEEEEEEEEEEEEEEEase dont use any more MA Startly on the little beast or it may not survive.
Good luck

[DmaxMaverick]

Welcome to TDP!

Believing the engine ran fine before, your experience is absolutely typical of an engine that has sat for 2+ years. I have resurected numerous 6.2's in the same manner, and they have ran for 10,000's, and 100,000's of miles more. The yellow junk you are seeing is a combination of raw fuel, that was introduced by wet starts (before the ether and good glow plugs), and rust that is in the cylinders, heads and exhaust. The fuel is just cleaning house. I do not suggest that an engine that has sat for so long be ran until an internal inspection can be done, but you are already past that. What damage that can be done, has already been started. It is more likely you have not caused any damage at all.

From this point, you do not have to remove the injectors or pump. If you have no leaks, leave it. A tank of fresh fuel with a good additive along with a qt. of ATF will clear out anything left. Be prepared to replace the fuel filter on a regular basis for a while. It is easier than removing the tank, which is probably not necessary at this point. Before you run that engine any further, check/replace the balancer. Very important! A bad balancer will not only make noise, but the noise you hear may be the start of a broken crank. Check the torque converter bolts as well, for the same reason, if it is an auto. Watch the fuel supply system closely for leaks to develope. Any leak that shows fuel, will suck in air when the engine is off, and lead to frustrating starts. As you rack up more running hours, things will loosen up. Valves, rings, lifters, etc, will take time to move freely again. The additional oil burning process all the while will be beneficial during this. Keep a close watch on the oil level, and for oil leaks.

As stated above, DO NOT use ether in a glow plug engine, even if the plugs are not energized. They will burn up from the excess heat, and swell in the hole. Removal of swelled plugs is no fun. If you got the old ones out, count yourself lucky. Also, which plugs did you install? Make sure they are not AC9G's, or another brand like Champion. They must be AC11G's or later. The 9's and champions are the OEM style plugs for the original M/Y, and can burn up and swell over time, or if over charged. TDP advertisers will have the best answer for your plugs. I realize you've already spent the bucks for plugs, but assure yourself you didn't install a headache waiting to happen.

Good luck with it, and be sure to come back with any other questions or problems.

[rodolforuiz]

Robyn C52 and DmaxMaverick,
Thank you both for your responses, they have been of great help. I'm very glad to have become a member of TDP and to have found a group of people that feel passionate about diesel engine. TDP offer quite a bit of information on diesel engines. I beleive I got Cardianl rule #1 dowm path and promise not to hurt "the little beast" no more with starting fluid. I definetly affects the glow plugs, learned it the hard way. Although, I got all of them out one was needed 5 minutes of wrenching and 3 hours of patience, but they've all been replaced.

I was quite happy to hear your comments, speacilly DmaxMaverick seems to have had the same problems with the old 6.2L. Glad to see the "yellow junk" is due to wet starts and hopefully as iddling/running time goes on this problem will go away I will no longer call her smoky. I've seen in other posts here on TDP references to engine cleaning additives that are mixed with the engine oil? what's your take on that? would you recommend it or would your recipe of a fresh fuel tank plus ATF and diesel additive will do. Definitley plan on changing the fuel filter as often as needed. I tried opening each injector one by one to let any air on the system out, some of them will make the engine rpm died down, however, not all of them did. In fact, one is particularly hard to get and was not able to open it fully, this is the one cylinder closest to the firewall on the passenger side. I'm afraid to damage the injector, any suggestions here?
In your pint regarding "check/replace the balancer" my ignorance does not help me there, are you talking about the harmonic balancer or something else? Regarding the transmission, yes it is an automatic transmission, it goes only up to 3rd gear, not sure what type of transmission is in it. One thing I noticed on it is when shifting it sort of jolts when goin from one gear to the other, specially when going from second to third, it seems that the rpm needs to go high before it shifts. I will check the torque converter bolts before I do anything else.
Leaks? yes, the base of the fuel filter is leaking every now and then, I will definitely try to fix it and will check closely the fuel lines. Hopefully the filter base does not need replacing, seems to be a hard and probably expensive part to get. Since I'm talking about fuel lines, the hoses that arch from one injector to the other in sort of a daisy chain, are they part of the return fuel line back to the tank? do they need replacing or should I leave them for now?

I will double check the type of plugs I got, kinda of trusted what they gave at Napa (did not know TDP existed!), but now I see there may be an issue with them. Later down the road, will order some from the people who advertise on the TDP, anyone on particular? One last question, do I need to actually drive the truck to get the different internal parts to loosen up or woudl iddling 3-4 hours at the time would do?

Thanks again Robyn C52 and DmaxMaverick for your inputs, hope to continue learning from your experiences and to have fun in the process with the 6.2L. See you and I'll be looking forward to your comments and suggestions.

Rodolfo

[DmaxMaverick]

Good info. Stick with it.

The "balancer" is the harmonic balancer. Check it closely for rubber deterioration/hardening. The balancer is VERY important with these engines. If the rubber ring, between the inner/outer steel, is hardened, or really soft and seems to be "oozing", the balancer needs to be replaced. Failure to do so may cause a broken crank.

While idling an engine you are not sure of is not a bad thing, it really needs to be loaded. Idling really doesn't get things loosened up. If your cylinders don't get up to temp, cylinder wall washing can happen. That's when the cylinder temp doesn't get up enough to burn all the fuel, and the "wet" fuel deprives the cylinder walls of lubrication.

Transmission.....
Your truck is a 1985 2500. You should have a TH400, 3 speed auto. One of the all-time best trannies for heavy use, but lacking in the gear ratios, and doesn't have a lock-up converter. Either way, shifting problems are usually due to vacuum modulation issues. You must have a good vacuum pump, operating vacuum regulator valve on the pump, and vacuum modulator valve on the tranny. Check all the vacuum lines for cracks, etc, and the vacuum pump should be building ~21" of vacuum. If the vacuum at any point can't be maintained above ~15", there will be shift issues. If you don't find any vacuum stuff like I described, and there is a cable (TV cable) on the driver's side of the injection pump, that goes to the RF of the tranny near the dipstick hole, then you have a 700R4, and you are not finding 4th gear. Some of the light duty 2500's (7200 GVWR) did have a 700R4, but I don't think they did for '86. If the engine is OEM, and doesn't have EGR, you do not have a 700R4 tranny. Also note that a well built 700R4 is an excellent upgrade for heavy duty use. Expensive, but very functional.

The ATF in the fuel does a couple things. It will up the fuel viscocity a little, and the solvents/detergents help to clean things up, as add a little lubrication. Also use a good cetane boosting fuel additive to offset the effects of poor/contaminated fuel. Also, frequently open (engine running) the fuel filter water drain to reduce sediment/water buildup in the filter. That leak you see at the filter base could be a leaky drain or connector, but there are also issues with filter housings leaking. I don't know the thread off-hand, but try a search for the fix. Address the leaks one by one, but make sure you get them all.

The injector return lines are necessary, and do return fuel to the tank. If they don't leak, don't mess with them. JK, www.kennedydiesel.com (http://www.kennedydiesel.com) , has a nice kit to replace them for not too much $$.

Once the engine is running reletively smooth, it is not necessary to open injector lines to bleed them. They will bleed themselves in a short time with the engine running. A few runs under load is all it takes. When changing filters, a lot of engine cranking may be necessary, so watch your starter/battery condition. Keep the starter cool by not cranking more than about 15 seconds at a time, with about a 2 minute rest between. The system is self-bleeding, but can take a while. If batteries get too low, you will cause more damage by continuing to crank it. The starter needs to maintain about 100 RPMs to start the engine, so if you are below that, you will just kill the starter. Take the time to charge them. Many folks have installed an in-line fuel pump to facilitate priming after filter changes. It really cuts down the cranking. More on that if you are interested.

Anyway, stay with it. You might have a good runner, and there's nothing better. I hope we got all your questions answered.

[rodolforuiz]

DmaxMaverick,
It's been over week now since your last reply. Before posting mine, wanted to do a couple of things on the engine and trannie. Here is what I've done. Check engine compression, change engine oil, fixed diesel leak from filter base, check transfer and trasnsmission, finally top out differential fluids.
The ngine compression results are as follows:1-360, 2-320, 3-300, 4-360, 5-325, 6-400, 7-380, 8-400. The smokes continues mainly on the right (passenger side) exhaust and looking at the results that has 2 pistons with what may be low numbers. The balancer appears to be ok, did not see any oozing. The vacuum regulator on the TH-400(you were correct!) was way off, shifting has improved quite a bit. The transfer looks good. The oil and filter both on the engine and the trasmission got replaced, engine with Rotella 15w-40 plus Bardhal No-Smoking oil additive.
I have logged about 100+ miles and made trip over 60 miles on the highway without any events. The average fuel consumption is 8.5mi/g!!! wow something is wrong with this picture, need help on that one. So far no fuel or oil leaks, in fact after steam cleaning the engine I was surprise to see that no leaks so far. The glow plugs are ac60g or 60g which ever denomination is correct. To stop the leak, I got a fuel filter base from the 82-83 model, round filter with petcock on top and bottom of filter, is this ok or should I find the original filter base for the 86 model? the filter is a primary/water separator also.
At this point, should I replace the injectors or should I log more miles before doing that. The smoke is not as bad as it used to be, more at the beginning but diminishes gradually as the engine warms up. Highest temp I saw while doing 65mph on the highway was 200 degrees F, usually will stay arounf 180, is this normal? I plan on flushing the radiator soon. Ok one more thing, the rear brake line will need replacing, where can I buy the brake lines? The engine still a little rough while iddling, would this be a result of a bad injector or may be low compression cylinder?
That's all I got for now, sure I'll come back with more questions as i dig deeper into old smoky. I thank you very much for your time and help answering my questions. Final question, based on what you see, you I consider rebuild or wait until I estimate the oil consumption based on more miles, is 1 quart per 700-800 miles the rule? sorry I went back and forth, must be late!
Thanks again and look forward to your reply.
Regards,
Rodolfo

[DmaxMaverick]

Did you do your compression check on a hot engine, or cold. It must be done on an engine up to or near operating temp.

Stay with it. You certainly shouldn't be talking about a rebuild at this point. The Bardhal's, IMO, was not a good move. You need to let the engine use up any oil that it wants at this point. The additive may prevent freeing up stuck rings or lifters. Your compression #'s don't look too bad, but could be better. #3 and #5 are pretty far out of spec, but may improve with more runnning. I wouldn't do an overhaul on this alone. Your ECT's look good/normal. Your oil consumption is at the max. limit, IMO, but should improve as time/miles pass. If it doesn't get worse, it should be OK. I know of some ppl that are using a qt/500 miles and are OK with it, but it all depends on how it's getting out of the engine. You are lucky to not have leaks. My '85 uses about 1 qt. about every 1500 miles, but it mostly ends up on the outside of the engine, or on the ground. I won't park it on a friend's driveway.

Injectors....Wouldn't hurt. You will likely be replacing them in the near future anyway, and there's no time like the present. This may also clear up some of the smoke and boost your MPG's.

[rodolforuiz]

The compression was done on a hot engine. Hopefully that's the case, no rebuild needed; it would be nice so I can put that money on the body of the truck. I will change the oil again and make sure Bardahl is out of the picture until later on in the game. I've seen the prices from usdiesel.com and the per injector rebuilt is about $40, they advertise on TDP. I'm not up to speed with the diesel engine lingo just yet, what's IMO and ECT (engine compression test?? my educated guess!). I will do the compression test again once I put 1000+ miles on the engine. Will post the results here.
Thanks for your inputs, they've been great help.
Rodolfo

[DmaxMaverick]

IMO = In My Opinion

ECT = Engine Coolant Temp

I haven't had to price injectors in a long time (knock wood). Kennedy has reman's @ $35. Check with all the DP advertisers. You can't go wrong with any of them.

[rodolforuiz]

LOL...it's good to laugh at your own ignorance, it always sounds like a logical explanation once one sees the answer. I'll check the prices from the TPD advertisers and order them today. I'll post any changes I notice after the injector replacement. Thanks for following up with this thread.
Regards,
RTRG

[rodolforuiz]

Hello again!
It's been a wile since my last reply. I got the injectors from USDIESEL.com $37/piece plus $25 on the installation kit which includes returning lines, washers etc. I'm taking off the intake head today, it's been hot and fun doing this glad that this is my second car so I still have reliable transportation for work. I was wondering if anywhere in this page we got the torque values for the intake head? also, the cylinder order for the 6.2 86 GMC. Most likely I'll be putting things back together tomorrow and will need to know the values? Thanks for any help.
Regards,
RTRG

[john8662]

http://www.thedieselpage.com/members/torque.htm

[rodolforuiz]

Thank you John8662....got it, now is time to install the new injectors, it's been fun taking things apart, hopefully everything goes back together the way it was! I've learned quite a bit from this page! just got to wait for it to cool off a little it's 94 out there!
Regards,
RTRG