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4020 Diesel problem

H

Heath72

Member
I need some expert advice...I ahve a '68 4020 diesel. My problem is that it is slobbering excessively out the stack and down the side of the manifold and down the engine block. It has 25 hours on a new inj. pump and injectors. I also reset the valve tappets at that time.

Here's what I have done to trouble-shoot: checked and fine-tuned the timing a bit.(it runs and sounds great with almost no blowby and the exhaust is clear with a slightly black tint), I cracked the injectors to see if there is a miss...every cylinder firing. The temp gauge needle comes up after about 10-15 minutes in cold weather. Sometimes it comes up about half-way(to the "N" mark), on colder days, only comes up about 1/4 of the way.

The last thing I did was remove the manifold for planing because I thought the front port was leaking. When I got it off, I could see that #1 chamber was wet. Maybe a bad valve/valve guide/valve seal? It runs so good that I can't imagine it being a bad cylinder. What do you think?

Thanks!

Heath
 
Check your oil level and see if it is over full. If so you have a leaking primary fuel pump or a cut seal for the injector pump fill your crank case with fuel.
 
I was going to say it just needs working/warmed up. But with your narrowing it down to #1, I would be suspicious of that injector. Or, is that just running back down into #1 after shutdown?
 
Have had trouble with chore tractors slobbering in the Wintertime when they were only used for a short time and never 'worked'/got up to operating temperature.
 
How did you check the timing? Only correct way to check, that I know of, is with the engine running at operating speed with a timing window bolted to the pump. Or, if you're experienced, a timing light with a diesel-adapter.
 
Static timeing on a 4020 is more than good enough, you most likely got an injector that is "slobberin" a bit, if you had it hooked to a plow for a couple of hours the 'wet stacking' would not show up, without any history I would change out all the nozzles and go on from there,that will most likely take care of it.
 
It still does it after being warmed up. The engine was overhauled around 1997, and doesn't have alot of hours on it since. The previous owner hobby farmed with it. I have a feeling the slobbering has been going on for some time, because there was alot of oil staining on the left side of the motor when I bought it. Looked like it was power washed off, but you could see where it was. Didn't think much about it at the time.

One of these days when I'm not busy PLOWING SNOW, I'll pull the injectors and have them checked. Thanks for all the input...I appreciate it!

Heath
 
Sorry, but that is rediculous. If the injection pump is known to work well, then yes - the static timing is all that is needed.

How do you know it's working well without checking?

One of main wear points on the DB and CB pumps is the timing advance. That's why Deere considers checking timing advance as part of a proper "tune up." It's also why Deere special ordered those pumps with an easily adjustable advance screw.

4020 is supposed to get a timing advance up around 16 engines degrees. That is a lot, and if it's not happening it can make a big difference in performance.

4020 is supposed to advance 2 engine degrees by 1000 engine RPM.

Advance 10 degrees by 1600 RPM.
Advance 16 degress by 2400 RPM.

Please explain to me how a static check of the pump tells you that pump is advancing to 16 degrees when running?
 
I can't tell you that,,I just know that more of them are static timed than not and go on running just fine, sure there may be a few 'unusual' instances...They are a very "user friendly" tractor as every one knows, and basic timeing is normaly enough,,,and no I don't want to argue about it....
 
I've had to fix many that ran awful because the timing was not advancing. That applies to all Deere tractors that use Roosamaster/Stanadyne pumps (except some very early ones).

Also applied to many Chevy and Ford diesel pickup trucks. Lack of advance is the #1 reason for pump teardown.

Makes no difference if it's a Deere 1020 or a 4020. They all need the advance working. And, there have been many problems with low sulfur fuel wearing out the advance mechanisms in these pumps, so they are wearing out faster now, then before. Stanadyne has a special kit to offset that wear when run on low sulfur, winter fuel, or military fuel. It's become standard equipment in Iraq on Humvees that have similar pumps made by the same company.

In this guy's sitution, he said the pump was recently repaired. So, it ought to be fine, but not every shop does every job correctly. At least, none that I know of.

A timing window to fit that 4020 cost $6-$7 and it takes ten minutes to check and adjust. Seems it ought to be a no-brainer to just check when in doubt.
 
Yes the the "new" fuels do pose a different set of problems now, and a lot of times the users don't relize their fuel is different, it gets changed without warning from the supplyers, it's tough on o-rings and couplers,,it's a problem that we didn't have back in the older days, but need to pay attention to now.
 
Heath i have overhauled a lot of 4020s and you need to hold the valve seats right on spec or you will end up with a hard starter and wet stacking in cold weather
 
I do use the Stanadyne diesel fuel additive in every fill since I bought the tractor. It's supposed to be pretty good stuff. Would be spendy if I was using the tractor alot, but this is just an acreage/snow moving/fun tractor, so it doesn't add too much expense for me.
 
Like I said, the tractor runs good with clear exhaust and almost zero blow-by, so naturally, I now suspect it to be a valve problem. The pump and injectors are practically new. I suppose it's possible for a injector to be hanging up, but not probable. Still wouldn't hurt to pull the #1 and have it checked. I drive by the diesel injection place on my way to work. Thanks for the input!

Heath
 
Here is a pic. All this is from the last 15 hours of run time.
a8629.jpg
 
Say Heath...in this pic, is the ventilator pump on the engine capped off instead of being fed from the air intake hose?

On my 4010, there is a pipe that connects that ventilator pump to the air intake. Just curious from you (or others that wish to chime in) if there is any issues with capping it off.
 
Start engine up when cold and run wide open throttle right away. If engine flutters and misses then advance static timing 2 to 3 degrees. Did you check valve lift? You might have a worn cam.
 
Around 'here', the John Deere mechanics (there were no techs back then) cut and crimped them all soon as they were out of warranty.
 
Yes, mine is capped off. It was that way when I bought it. I think in '69 they eliminated them altogether. I repleced the rubber seal and the gasket before I painted the tractor in May. It looked like it was leaking a little.
 
Looks to me like it needs the crap pulled out of it on a plow or chisel plow. would dry up in abt a day but will come back if your piddling around and not running it hot. Needs 180 to 202 thermostats as well. cover the radiator if its really cold like it is here. Also you could swap the injector to a different cyl .
 
When you do away with them gear and all you need to plug off the oil pressure feed hole in the block, I sink the right size ball bearing in the hole and stake it.I always wanted to find a bore plug that size to cap off the big hole, but it's an odd size...
 
When you say new pump and injectors, were they new or rebuilt? Where did you get them? What kind of injectors does it have? Pencil or the large style?

I recently saw a 4030 that had been overhauled (new pistons, liners, injectors) that slobbered. Turned out it was valve guides that had been worn. The replaced the guides and valves and it went away.

If when it was rebuilt it didnt get broken in properly, it could have not seated completely and may no be getting a good burn.

I would suggest checking the timing and injectors just to make sure they are good. Then find a dyno and work it for a few hours. It wouldnt hurt to run some Deere break in oil in it to be safe. Deere recommends 100hrs of this after an overhaul with normal work conditions.

Good luck
 
I had the pump and injectors gone through a our local injection shop. They have been in business for a long time and do good work. Many Implement dealers use them as well.

When I bought this tractor, it had a flutter between 1000 and 1300 RPMs. When I picked the pump up, the guy said it had a bad tensioner ring. This one has the pencil injectors by the way.
 
Your tractor needs to go out and work. Get it on a plow or fitting tool. That kind of slober was real common on 4020's and 3020's that were used to run portable grain dryers and sat and ran at high rpm without much load.
 
Since you got a pretty good feeling it is #1, do a compression check against the other cylinders, but it does sound like it needs the snot pulled out of it

Tim is right also, injectors are a great place to start and one slobbering bad will make the exhaust slobber

I am suprised the 'correct police' haven't jumped all over you for saying you have a 1968 4020

It is 1967 or older
 
i had some dealings with Cat on generator engines with the smae problem. People would let them run with no load and they start to "slobber". I suggest you work the tractor. If you have access to a dyno it can really help with diagnosis.
 
Actually I should clarify that. It is the 100th 4020 built in 1968. SN/174082. I have seen other '68 models a high as #600 that still have the round air intake as well. They probably had to use up all of the old ones first.
 
Heath72, Did you advance timing yet? Scratch a mark across pump flange and engine, then move marks apart about the width of a dime.
 
Yes I did, that's about how much I moved it. It has a more positive sound now...a slight bit more "diesel knock". Comparing it to other 4020's I've driven, it sounds good to the ear. It still is spewing about the same though. I think I will first pull that #1 injector and have it checked, if that's OK, I'll pull the head come spring and have it gone through.

Thanks

Heath
 
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