Thread: TD5 Possible bent rod

Would a bent rod make a noise? Probably not. Was the engine ever hydraulically locked that makes you suspect a bent rod?
What about pulling the glow plugs and having a look with a borescope. Is there any chance that the change to a new head is causing valve/piston interference?

Col surely a bent rod would shorten its length thus having the opposite effect to what you are describing.
If it wasn't doing it with the old head maybe the valves are not recessed into the head as far as they were on the old head.
As much as its a PITA maybe a thicker head gasket will resolve the issue??
Assuming that there is slight contact between a valve and a piston so slight that its not noticeable when you wind it over by hand.
Having read over the years the abuse that your car has had I am surprised that you got away with a standard head for as long as you did

Hi. Perhaps post a little video of engine at idle.. if possible.. You say it was down on power before you pulled the head...? Down with a misfire, or just lacking power? If (and I say if) the oil was so diluted with diesel that it causes you to suspect a big end bearing, it could have done a few things... Little end bearings etc.. Is it worth dropping the sump off and having a look? I gather by a previous comment that this engine has been chipped, boosted, etc etc?? If you are looking for big power reliably in a hot climate, then you have to look at a bigger motor.. 2.5 litres has its work cut out dragging 110's and 130's around from day one... Let us know what more you find. Cheers for now.

Col, the knock could be a damaged piston skirt/ bore due to inadequate lubrication. the oil jets that supply cooling oil to the pistons also act as lubrication for the bores, especially on cold startups. the below pics are a result of no oil supply to a piston skirt/ failed piston oil cooling jet IMO, thrust side damage and heavy knocking at idle. no other bores or pistons effected, no other engine wear or damage anywhere else.

jc

Did the knock exist before the head change?

its unlikely but it could be the gudgeon shoulders.... Ive seen a 4bd1 that was run with the wrong oil in it that hammered the gudgeon pin shoulder oval (it was a trainee engine, one of those find the knock jobbies)

Id suspect a big end gone. easy enough to test, pull the glow plugs, put the spanner on the crank and turn it over as each pot comes up to TDC and BDC rock it back and forth a little see what noises you get.

bear in mind that if its thrown sideways you'll get the knock as the pot comes up past 90 degrees.

G'day all, many thanks for the thoughts & comments.

After reviewing the comments I went out & started it up again & took a video with the Wife's Iphone (just gotta work out how to attach it here) & the noise is getting markedly worse, I think the noise is coming from the piston area, on TDC but it is hard to be sure, it is a definite knock now such as the gudgeon floating around or similar in the piston or along those lines. The only course of action now is to rip the engine out & strip it down to find the problem. As most of it is all fairly new if there is no crank or block damage & the issue is confined to one pot I recon the damage will be in the region of about a thousand bucks for a new piston, rod if needed, gaskets bolts bearings etc. It is a shame I found the bottom end damage after putting it all back together again, what a waste of a set of head bolts gaskets etc for 10 minutes worth of idling.

To go back to the original problem the engine was down on power but still running OK, EGT & boost were higher than usual and engine block temp was running about 10 degrees hotter, I stopped on the side of the road & had a quick look & could see no obvious problems, sadly I didn't think about checking the oil level so pressed on home which was about 30km as I had our 3 year old son onboard & it seemed OKish so I took it steady & it got home OK. Once it cooled down I checked & cleaned the injector harness plug incase of oil ingress & started it up again, it idled OK but was not right, so I pulled the dip stick out with it running & oil/fuel was bubbling out. Then the penny dropped and the rest is history.

As for the engine, yep it had a hard life before the rebuild but since then its life has been much better due to the onset of a baby & less time to drive in the desert. It has been chipped, VNT, larger intercooler etc,etc.

In hindsight it as the wrong vehicle for hard use in the desert, I had a look at new 4.8ltr GU Patrol this afternoon which is probably what I should have brought initially and may end up buying soon which is a shame as I have spent a lot of money on the 110 & it is well set up with almost every mod you would want to do to it.

We are off to the States for a months holiday this coming Saturday so it can stay as it is until I get back & can find the motivation to strip it all down again. Will keep you updated on the progress after the holiday.

Thanks again for the feedback.

Double check you have the accessory belt ribs lined up correctly on all the pulleys. I know it is a bit left field but recently changed the head on mime and thought I'd destroyed the engine from the racket. It ended up being the belt one rib off on the crank pulley.