6.2 Chevy motor? - Page 2 - PeachParts Mercedes-Benz Forum

#16 11-03-2004, 01:43 PM

Quote:

Originally Posted by rwthomas1

Removing a Stanadyne pump is easy. Remove air cleaner or turbo intake pipe, 6 bolts and 1 clamp. Remove intake manifold, I think its 12 bolts. Intake is not connected to coolant system so that doesn't have to be drained. Remove the 4 upper injector lines completely. The lower lines may simply be detached from the pump and left hanging. Remove oil filler and index crankshaft to remove pump timing gear bolts through access hole. Remove 3 pump retaining nuts, two fuel lines, unclip accelerator cable and CC cable, stop solenoid wire and the pump is in your hands.

Yep, easy

psfred · #17 11-03-2004, 06:38 PM

Noisy, smoky, very low rpm vs the benz, but keep good oil in in and ignore the marbles-in-a-coffeecan stuff and it should run pretty well.

Crank probably breaks ithrough the journal sides like the one in the 300D did -- you get a deep bearing knock on acceleration and at idle -- sounds like someone is thumping on the block with a 5 lb sledge. Do not ignore this noise, it's the crank flexing on the loose crankpin! Eventually the other side will go as well, and the rod and crankpin, no longer attached to the rest of the crank, will get driven through the side of the block. Not pretty, engine is toast.

Peter

bill murrow · #18 11-03-2004, 06:40 PM

You would think there would be more than shaking if the crank was broken. I would think there would be some seroius knocking as well.

I had an '84 Suburban with the 6.2....don't worry about lugging it.

When I bought my first Benz diesel I was worried about how high it revved, being used to the low RPM of the 6.2. Drove that truck 5 or 6 years and never had a moments problem with it. Anemic as heck being a non-turbo but super fuel mileage. I got 23-25 regularly and the worst I got was 13. I was pulling a 24' camper into a headwind with my foot to the floor for 5 hours.

I always ran some sort of additive to keep the fuel clean and water free. Changed the fuel filter regular as well.

To sum it up, I loved mine, it was reliable and gave me great service. Good luck with yours.

Cheers,

Bill

boneheaddoctor · #19 11-03-2004, 07:20 PM

Quote:

Originally Posted by psfred

Noisy, smoky, very low rpm vs the benz, but keep good oil in in and ignore the marbles-in-a-coffeecan stuff and it should run pretty well.

Crank probably breaks ithrough the journal sides like the one in the 300D did -- you get a deep bearing knock on acceleration and at idle -- sounds like someone is thumping on the block with a 5 lb sledge. Do not ignore this noise, it's the crank flexing on the loose crankpin! Eventually the other side will go as well, and the rod and crankpin, no longer attached to the rest of the crank, will get driven through the side of the block. Not pretty, engine is toast.

Peter

And that happens when the harmonic balancers fails.......and why its recomended to paint a white strip across it. Takes a LONNNNNNNG time to fail but when it does its inportant to replace it post haste. When the white stripe no longer lines up its time to change it. That is what causes block and crank failures............Run the 617 with a slipping harmonic balancer and its not gonna last "over 500,000 miles as is common for these engines"

bill murrow · #20 11-03-2004, 09:14 PM

Quote:

Originally Posted by boneheaddoctor

And that happens when the harmonic balancers fails.......and why its recomended to paint a white strip across it. Takes a LONNNNNNNG time to fail but when it does its inportant to replace it post haste. When the white stripe no longer lines up its time to change it. That is what causes block and crank failures............Run the 617 with a slipping harmonic balancer and its not gonna last "over 500,000 miles as is common for these engines"

You've been looking on Ebay too much.

They all go 500,000 don't they?

Cheers,

Bill

boneheaddoctor · #21 11-03-2004, 09:17 PM

Quote:

Originally Posted by bill murrow

You've been looking on Ebay too much.

They all go 500,000 don't they?

Cheers,

Bill

That seems to be the inside joke and catch phrase these days isn't it.

BobK · #22 11-04-2004, 07:30 AM

Is the truck a stick or auto? My '82 K5 Blazer had a 6.2 with 700R4 transmissin and 3.08 gears. Ran well, pulled well and got good fuel economy. Transmission was weak link. If you have same driveline as I did, watch out. Transmission is not strong enough for torque load at low RPM. I suspect 3.73 or 4.10 gears would have solved some of the problems. If you have the 3 spd auto, no worries. I did have the pump and injectors rebuilt. Cost about $700 for all and I did the labor myself. In my case the pump developed a serious fuel leak and I just did the injectors while I was there. truck had like 200k at the time. Only other pain was the glow plug controller. Little device screwed in top rear of block. When they go bad, they burn out glow plugs, as they just stay on! I liked the motor and I would really like to get a '99 6.5td sub. great tow beast. Rust of course is always the problem on the hills where I live live. They buy salt by the BARGE LOAD around here. Good luck with your truck. I think you will be pleased. I wish I could get my son to buy one just like yours.

bill murrow · #23 11-04-2004, 12:55 PM

Quote:

Originally Posted by boneheaddoctor

That seems to be the inside joke and catch phrase these days isn't it.

Yeah and I'm sick of hearing it.

Would NOT buy a car from someone who makes this statement. Funny how many put that into their sales pitch.

Cheers,

Bill

boneheaddoctor · #24 11-04-2004, 02:35 PM

Quote:

Originally Posted by BobK

Is the truck a stick or auto? My '82 K5 Blazer had a 6.2 with 700R4 transmissin and 3.08 gears. Ran well, pulled well and got good fuel economy. Transmission was weak link. If you have same driveline as I did, watch out. Transmission is not strong enough for torque load at low RPM. I suspect 3.73 or 4.10 gears would have solved some of the problems. If you have the 3 spd auto, no worries. I did have the pump and injectors rebuilt. Cost about $700 for all and I did the labor myself. In my case the pump developed a serious fuel leak and I just did the injectors while I was there. truck had like 200k at the time. Only other pain was the glow plug controller. Little device screwed in top rear of block. When they go bad, they burn out glow plugs, as they just stay on! I liked the motor and I would really like to get a '99 6.5td sub. great tow beast. Rust of course is always the problem on the hills where I live live. They buy salt by the BARGE LOAD around here. Good luck with your truck. I think you will be pleased. I wish I could get my son to buy one just like yours.

Mine has the bulletproof TH-400 transmission.....its only failing point is it has no OD so with 4.10 gear in both axels it get 14 mpg on the highway.

nglitz · #25 11-04-2004, 03:16 PM

Quote:

Originally Posted by crash9

Thanks – Now (if you’ve got the time) could you give me a grade school explanation for what the white line is for and exactly what we’re doing here? Does this really mean the lower end is weak? I’ve heard the term harmonic balancer, but am not completely clear on why you’d want to rotate it – seems like that would unbalance it? Sounds like something that could be fast, ugly, and with no warning.

The harmonic damper is essentially the crankshaft pulley. It has a heavy inner part and an also heavy outer ring bonded together with rubber. The torsional vibrations from power pulses in the crankshaft make the two damper parts wiggle and absorb some of the vibration. If the rubber bond breaks, the two parts don't absorb as much of the vibrations, making the crank twist more than it should. This sets it up for possible cracking. Also, the two damper parts could separate, causing damage when the outer flops around. the white line is a visual indicator that the parts are still bonded. This is a problem with some MB gas V-6 engines. Worth watching.

boneheaddoctor · #26 11-04-2004, 03:20 PM

And a white line can be checked when you check widshield washer fluid or whatever, in a second or two without even getting your hands greasy.

when the rubber bond breaks the inner and outer rings will rotate in relation to each other, a very bad thing. that would make the line no longer a unbroken line.

rwthomas1 · #27 11-04-2004, 06:07 PM

Crash, consider these upgrades:
Install a tachometer. The torque peak occurs at 1800-2000rpm so you don't have to spin it to get all it'll give. Autometer makes a nice diesel unit. What transmission is in it? A 3speed likely is a Turbo 400, indestructible. If its a 4speed then likely its a Turbo 700R4. These can be weak and its never a good idea to lug in OD. The reason is the pump is not supplying enough pressure at low rpms to keep the clutches from slipping and the tranny burns up. Running in 3rd is a partial cure but that is running with an unlocked converter and this generates a lot of heat. The easy cure is a quality "shift kit" from B&M, etc. installed with the "heavy duty" programming. An additional tranny cooler is highly recommended also. Th700's are almost impossible to over-cool. Consider installing a larger Racor fuel filter. The factory GM filters are marginal. Regarding the vibration damper take a good close look at it. The rubber ring will be clearly visible between the inner and outer metal rings. The rubber should be pliable, soft enough to depress with your fingernail and some effort. It should be uniform in appearance and not pooched out or have an uneven surface. There should be no dryrot. There is also a rubber mounted crank pulley on some models that has been known to fail so inspect that too. As I stated before try www.thedieselpage.com out. The membership is $20/year and you will save that easily with the same sort of advice that you get here on the MB forum and from the GM diesel parts suppliers that advertize there. Keep an eye open for a used turbo kit from Banks or ATS. They pop up from time to time and really wake the 6.2 up. Almost forgot to add you want to use AC60G glowplugs. They are a PTC design and do not burn out with constant power applied. The older AC9G's were good but they swell when overheated and can break upon removal. Not good. Enjoy, RT

crash9 · #28 11-04-2004, 09:56 PM

Thanks for all the feedback guys. I suppose we’re all about the same when it comes to boning up on a new purchase. I’ve really gone to school on this old girl in the last week. Joined the Dieselpage, but haven’t hit their forum yet, and how I’ve gotten this far in life without understanding harmonic balancers is a bit of a worry, but that’s now been fully covered.
The charm of this truck is that it’s never been out of Cochise County AZ, so that real rusty rot is no issue. It was a county vehicle and had a good maintenance schedule and I suspect an engine rebuild, as there’s really no blow by for 188,000 mi. It does have the 700R4 tranny and I’m gonna switch to a toggle switch for the GP.
I’m hoping to get buy with a kit for the TV but I’m sensing a rhythm in the converter when in OD, and that ones outa my league.
And now back to the Merc’s – what’s that funny noise I’m hearing when I turn ever so slightly to the right – sounds just like the PS pump, but it’s not.

P.E.Haiges · #29 11-04-2004, 10:11 PM

Crash9,

The 6.2 Chevy ENGINE originally had 6 volt GP in it so they would heat up faster. The controlller switched them on and off to keep them from burning out. If you use a switch, you will burn out the GP if you leave them on too long. I did on mine. A GP switch was installed by the PO.

12 volt GP are available. So I suggest you replace any with 12 volt GP and they won't burn out.

P E H

boneheaddoctor · #30 11-05-2004, 08:19 AM

I had to replace my crank pully in the spring as the rubber damper in it disintegrated and satarted to clang. Got a new one post-haste and figured since I was already there I should replace the Harmonic balancer. That was far cheaper ( harmoni balancer $112) than the crank pully (that was $325). I masked it off and painted a 1 inch while line through the center end to end. Not sure it was slipping yet but figured if one went the other might not be long from doing the same.

Now I can keep tabs on it for the future.....

And Mine will soon be turbo also........But not a banks or ATS kit.