Excessive blow by and oil leakage LDT465 1D

[BinderDan]

I’ve owned my 71 Deuce for about a month now, maybe a little bit longer but not much. I’ve put nearly 3000 miles on it including my 750 mile drive home with it. It has a lot of blowby, to the extent that I am continually battling with oil leaks (rear valve cover) to be the worst, now it’s leaking around the injection pump. The engine was a tead rebuild in 1988 at 11,000 miles the truck now has 16,500 or so on it. It was fire dept truck so I am assuming loads of idle time. I’ve loaded about 9k lbs on the old gal and ran it nearly 300 miles at highway speed two weeks ago hoping that would help, but no dice

Just wondering if anyone here has overhauled a multifuel, or if it’s even practical to do anymore VS engine swap to something along the lines of a DT466 or Cummins.
I can get my hands on one very low mile engine for about 500$ but in the long term would I be better off doing something different

Thanks
Dan

 

[cattlerepairman]

It would be helpful to see a video of the blowby.

Some reading: https://www.steelsoldiers.com/threads/ldt-465-rebuild.16455/

Blow-by assessment - opinions needed!

Did some PMCS on the truck today. It always had noticeable blow-by from the slobber tube. I am about to rip the valve covers off and adjust the valves and I thought I post a little video here to get opinions as to whether this is normal, questionable or downright bad. Engine is a LD-465 with a...

www.steelsoldiers.com

Note that the air compressor is a "must-check" when seeing blowby. Unhook the belt and run it without the air compressor, looking for change in blowby.

As for the leaking "around the injection pump", does it leak from the timing gear side or from above the injection pump, oil filter or head gasket area?

Valve cover oil leaks...the rubber gasket can become hard and a common mistake is to over-torque the valve cover bolts. It is a low oil pressure environment (oil basically just sloshes around in there) and does not need gorilla clamping forces.

You did the right thing by loading her up and taking her on an extended run. Often, that helps in freeing up rings and getting them seated after endless bouts of idling cause carbon buildups.

Unless the blowby is extreme AND the engine has problems, such as a knock or bad compression/a leakdown issue, I would leave it alone, adress the leaks and drive it.
OR you could simply swap in a good running takeout engine (if you are disciplined enough to leave the damn thing alone and just install it!). You can probably pick one up for $1000-1500.

Here is why I say that:

I have overhauled a good used LDS accidentally, by scope creep. All I had wanted to do was to drop it in as a good used running engine. The head gasket seeped a little and I thought "The engine is out, easy to work on...do I want to do head gaskets in a year, climbing up and down in the truck?"

Once the heads and oil pan were off, it was the the "well, while I have THIS off, it would be dumb not to do THAT" effect, basically.

Calculate a good $2k in material to do an overhaul. Sounds like a lot?
Yes, the small things do add up surprisingly quickly. Some are obvious, like springing $250 plus for a complete gasket kit. Other decisions can only be made as you inspect the parts you pull out. Are you going to keep the liners and pistons and just re-ring the pistons and hone the liners, or are you dropping in new sets into each hole?

Are you keeping the heads and have them machined and cracks welded (if required) or are you going with new heads ? New crank and rod bearings, obviously, new crank seals. No surprises with the lifters and push rods? Can you leave the crank and camshafts alone or do they need work? Is it time to do the IP hydraulic head o-rings while everything is conveniently accessible? And so on and so forth.

It is a fun project to do, A great time to swap the LDT rocker arms for a set from an LDS More power, baby!

 

[BinderDan]

It would be helpful to see a video of the blowby.

Some reading: https://www.steelsoldiers.com/threads/ldt-465-rebuild.16455/

Blow-by assessment - opinions needed!

Did some PMCS on the truck today. It always had noticeable blow-by from the slobber tube. I am about to rip the valve covers off and adjust the valves and I thought I post a little video here to get opinions as to whether this is normal, questionable or downright bad. Engine is a LD-465 with a...

www.steelsoldiers.com

Note that the air compressor is a "must-check" when seeing blowby. Unhook the belt and run it without the air compressor, looking for change in blowby.

As for the leaking "around the injection pump", does it leak from the timing gear side or from above the injection pump, oil filter or head gasket area?

Valve cover oil leaks...the rubber gasket can become hard and a common mistake is to over-torque the valve cover bolts. It is a low oil pressure environment (oil basically just sloshes around in there) and does not need gorilla clamping forces.

You did the right thing by loading her up and taking her on an extended run. Often, that helps in freeing up rings and getting them seated after endless bouts of idling cause carbon buildups.

Unless the blowby is extreme AND the engine has problems, such as a knock or bad compression/a leakdown issue, I would leave it alone, adress the leaks and drive it.
OR you could simply swap in a good running takeout engine (if you are disciplined enough to leave the damn thing alone and just install it!). You can probably pick one up for $1000-1500.

Here is why I say that:

I have overhauled a good used LDS accidentally, by scope creep. All I had wanted to do was to drop it in as a good used running engine. The head gasket seeped a little and I thought "The engine is out, easy to work on...do I want to do head gaskets in a year, climbing up and down in the truck?"

Once the heads and oil pan were off, it was the the "well, while I have THIS off, it would be dumb not to do THAT" effect, basically.

Calculate a good $2k in material to do an overhaul. Sounds like a lot?
Yes, the small things do add up surprisingly quickly. Some are obvious, like springing $250 plus for a complete gasket kit. Other decisions can only be made as you inspect the parts you pull out. Are you going to keep the liners and pistons and just re-ring the pistons and hone the liners, or are you dropping in new sets into each hole?

Are you keeping the heads and have them machined and cracks welded (if required) or are you going with new heads ? New crank and rod bearings, obviously, new crank seals. No surprises with the lifters and push rods? Can you leave the crank and camshafts alone or do they need work? Is it time to do the IP hydraulic head o-rings while everything is conveniently accessible? And so on and so forth.

It is a fun project to do, A great time to swap the LDT rocker arms for a set from an LDS More power, baby!

I’ve been running fairly regular, pulling trailer with it once and awhile, blowby seems to have improved some, but still not the best, has developed a fast tick, I ran overhead again, valve cover gaskets were new. Seems like possibly scored piston. I’m going to pull it down, new sleeves and pistons have the heads checked and replace front and rear seal. Then its done.


Cattlerepairman, could you give me a call if you have a moment. 507 402 3337.
Thank you