Thread: Run in period

Originally Posted by Dougal

Start it, let it idle just long enough to check that everything is okay (i.e. not ****ing oil or water through something I forget to reconnect).
Then get it in and drive.
Short trip (like around the block) and again check everything is holding oil/water.
Then longer trip to get it warm. Once cool afterwards recheck everything, incl head bolts if you're doing it that way.

First part the same as Dougal. However for the first 5000 km I make sure never to sit at a constant speed or let the vehicle idle for more than 30 secs at a time. Little/no highway driving. I usually find somewhere hilly to drive so everything beds in.

I used to know an engine reconditioner who had the contract for Army 4BD1(T)s. They were run in on a dyno - under varying load.

Originally Posted by Dougal

I'm no expert, but this has worked for me.

Start it, let it idle just long enough to check that everything is okay (i.e. not ****ing oil or water through something I forget to reconnect).
Then get it in and drive.
Short trip (like around the block) and again check everything is holding oil/water.
Then longer trip to get it warm. Once cool afterwards recheck everything, incl head bolts if you're doing it that way.

Then drive as normal.

Pretty much that, although after was all good and about 300km's later, I hooked a 750kg trailer on the back and drove to Sydney and towed another range rover, with 400chev, PTO winch and bits, somewhere around 3200kg's at a guess home, It's now sitting in the shed some 40,oookms later, I'm just waiting to see how long the one in my 120 goes for

a bit off topic but i have built a few donks in my time but my 300tdi was the first diesel all i really did for a run in was kick it in the ribs 5 mins running in the shed while i had a beer and a smoke and checked for oil/coolent leaks ran it round the block came back another stub and a smoke and looked for leaks topped up the coolent wacked the bonnet back on and drove it home 40,000 k later and and its spot on but long periods of idle for a diesel are a killer they love to work but remember the fuel being injected is a lubricant and glazed bores is what you will get after long periods of idle . even just ploding around in first or second gear is better then letting it idle

G'day All, Hopefully I will be driving my 110 Isuzu this afternoon after a full rebuild, I know I will not be letting it idle, might take a night drive up through the Broken Back range cheers Dennis

Back in the older days, especially with cast iron cylinder bore and rings the quickest way to run in was to drive so there were alternating small period of coasting followed by high load.

What then happened was while coasting low cylinder pressure helped to draw lubrication up around the rings, in preparation for the high pressure behind the rings during the high load.

Now with hard chrome plated rings, they take a very long time to bed in - so the above procedure doesn't work as well.

Further to this the Isuzu liners have a hard chrome plating that has some porosity to hold lubricant.

The improved precision plus hard chrome plating of wearing surfaces means bedding in is not normally required, but high loads for extended periods should be avoided between coasting periods (for upper cylinder lubrication - as above).

Originally Posted by Bush65

Back in the older days, especially with cast iron cylinder bore and rings the quickest way to run in was to drive so there were alternating small period of coasting followed by high load.

What then happened was while coasting low cylinder pressure helped to draw lubrication up around the rings, in preparation for the high pressure behind the rings during the high load.

Now with hard chrome plated rings, they take a very long time to bed in - so the above procedure doesn't work as well.

Further to this the Isuzu liners have a hard chrome plating that has some porosity to hold lubricant.

The improved precision plus hard chrome plating of wearing surfaces means bedding in is not normally required, but high loads for extended periods should be avoided between coasting periods (for upper cylinder lubrication - as above).

As the diesel mechanic who rebuilt the cummins in the truck said "Drive it like you stole it!" In other words work it hard to bed the rings in or it will glaze the bores

Cost Effective Maintenance FTC is ideal for sorting this type of issue out in my experience.

Cost Effective Maintenance - FTC Decarboniser

used it on a few engines including my 4bd1t with excellent results.

use it in my VW diesel so it keeps the particulate filter cleaner.