Engine Woes

[Gish]

I'm having an issue with my engine i'm hoping to get some advice on.  I have the 2.5 NAD in an ex batus truck, last fall I had TRS do a reseal and timing belt replacement (As I don't have the space and tools to do the job) and used the truck twice before storing it for winter.
I recently brought it back out and went out with a friend who was bugging me how slow it was, and yes I know it's slow as it's a 12J with a military LT77 gearbox.  Turns out though it's even slower then I thought as my speedo is actually 10Km/h slower then showing! Measured it with a GPS speedo app and when I thought I was doing 100, it was actually 90.  Tires are 7.5R16 (which is another problem i'll have to tackle)

On top of that it was smoking like a chimney tons and tons of White smoke.  After looking up online it was suggested it was due to timing being off and a tweak would be to move the pump a few mm.  I've tried that and I think I may have messed up, now it still smokes and I can't get the truck faster then 80km/h at all. Reset it back to what it was now but  I've spent a few hours tweaking it here and there but at this point i'm frustrated with it and will probably just take it in to get fixed.

So my question is would timing be a major issue with overall speed/performance?  Would there be anything else to look at? 
So far i've checked the major items as suggested in the manual that I'm able to do with my limited resources such as the air filter (Clean) fuel lines (Seem ok) belts (tight as per manual) not sure what else to check at this point.
Help! i'm getting pretty frustrated.

[Red90]

You can check the injector spray pattern.

It could be deeper into the engine as well and starting with a compression test would be good.

When you adjusted the timing did you make sure that you advanced?

The speedos always read 10% high.

Running properly you should be able to do 110 at Calgary altitude on the flat with no headwind although the 1.6 box may prevent it getting quite that fast.

[Red90]

I would also run a heavy dose of fuel conditioner. Powerservice grey bottle. Give it like four times what is suggested.

[Matt H]

Wait, you got 90kph out of 2.5NA?

Seriously though, that's not an altogether unusual KPH figure. Especially if the engine condition is unknown and the vehicle has been laid up for long periods.

Once you are happy with the timing and you have checked engine compression etc try just putting it to work. Find a heavy trailer and a long hill and make that SOB work. Get it good n hot and blow some of that coke out.  The 2.5 is an incredibly rugged unit and is built to work. Light loads and occasional use with long dormant periods don't do it any good at all. 


Sent from my iPhone using Tapatalk

[Johno753]

I refreshed my 2.5 ha new bearings,rings,gaskets and seals and with the 1.6 transfer box I was getting 103 kph with the wind behind me

[ugly_90]

I've said it before, and will say it again.

You really can't assume anything with these or any other old engines. The newest in a registered vehicle is 15 years old, and most are 20-25 years old.

Having been bitten once, they were good engines when new, but without a full reputable teardown, inspection and rebuild, everything is suspect, particularly an uninspected top-end. Too many shots in the dark for servicing. It isn't like a newer engine just out of warranty when you can assume only one small fault causing a larger problem.

A splash of green military rebuild paint is no indicator of anything ever having been done right on that engine, so goes the story.

You're really spending good money on bad equipment.

That said, it seems the 2.5NA is a poor choice for roaded longer wheelbase landrovers like the 110 and 109, a more powerful engine seems like a better use of time and money.

The 2.5NA may suffice for something like a 90 or an 88. You'd be well advised to choose a rebuilt turbo diesel for your 110, and there are several options for that.

The most common of course are the 200 and 300tdi. If I had a larger fleet, a shop, and was retired, I might even choose something like the Mercedes OM617, although there are drawbacks there too.

[binch]

Surprise, Surprise....it's all old news learned by serveral of us already. ;)

[Matt H]

Nothing really wrong with the NA  2.5L in my opinion. They are just old tech and slow revving that's all. But they suited the military 110's and off road work perfectly. They are tough and reliable and installed in utility LR's that are themselves designed to go slowly anyway.

Obviously a fully rebuilt engine is nice but you don't need to be throwing the baby out with the bath water. A rebuild is certainly not mandatory or even required in many cases to gain a good condition, reliable engine. Effective, methodical troubleshooting will reveal most issues and if the rebuild/re-power was undertaken simply out of frustration rather than sound diagnosis then you run the risk of wasting money or even damaging a new unit with the existing external components that are likely in worse shape than the engine having never been serviced at all. like fuel, radiator, oil coolers etc.

I wouldn't go through the hassle of fitting an old MB diesel. They are just as outdated as the old LR units and no more reliable or powerful. 

My 2c.