Td5 cracked head and bent rod

[Davetd5]

Hi Folks
I have a suspected cracked head on a 9/02 D2a Td5 at 319,000km
I've owned this for 10 years since it had 100,000kms
I replaced the head gasket 7 years ago at 180,000kms

I'm losing coolant and the engine is hydraulically locked if left overnight.
I suspect #1 cylinder as that exhaust port looked darker than the other 4 when I had the manifold off recently

I'm planning on ordering a new head from Turners, and TRS told me I probably have a bent rod also.

So I have some questions please for anyone who's done this:

1. How can I tell if a rod is bent? Do I use a dial indicator, or a feeler gauge to check the piston to deck height?

2. At 319,000km can you just put another rod in, or should I replace all the rings and bearings (like I would in a petrol engine at these km's)?

3. Timing chain replacement at this mileage?

Planning to keep this vehicle for about another 3 years and then upgrade to a D4

Thanks Dave

[INter674]

TRS......mmmmm....no comment😎

[justinc]

A used long engine, with a new head gasket fitted and oil pump bolt checked is likely the cheapest method. You will find the bore in the cylinder with water ingress will be trashed, a bent rod is a huge labour job and there is also no guarantee the crank isn't compromised, either. Don't forget these have micro toleranced bearings and fracture cap conrods. Totally different deal to just replacing the good old school rods,

J

[discorevy]

I've also seen the egr cooler on the D2a's let go , causing hydraulic lock ........worth checking.
last one was around three years ago and happily still going strong with no issues

[Davetd5]

I've also seen the egr cooler on the D2a's let go , causing hydraulic lock ........worth checking.
last one was around three years ago and happily still going strong with no issues

Thanks, I've got the EGR delete so I assume that shouldn't be a problem?
The cooler is still there but there's no EGR valve anymore

[Davetd5]

A used long engine, with a new head gasket fitted and oil pump bolt checked is likely the cheapest method. You will find the bore in the cylinder with water ingress will be trashed, a bent rod is a huge labour job and there is also no guarantee the crank isn't compromised, either. Don't forget these have micro toleranced bearings and fracture cap conrods. Totally different deal to just replacing the good old school rods,

J

Thanks Justin,
I'd be doing all the labour myself (I was a Ford mechanic in a former career), but if the bore is stuffed then that's a worry.
Just curious, do people rebuild/ rebore these engines, or is it not worthwhile cost wise?

[INter674]

20 thou max rebore...plenty done with rebore and oversize pistons according to eng rebuilder in tassie...mine was done that way....cost @4k for full rebuild inc head reco...german pistons. .....kobleschmitt or suffin😕

[Davetd5]

20 thou max rebore...plenty done with rebore and oversize pistons according to eng rebuilder in tassie...mine was done that way....cost @4k for full rebuild inc head reco...german pistons. .....kobleschmitt or suffin😕

Thanks, I wouldn't mind calling them. Could you please send me their name or details?

[INter674]

Pm sent

[Davetd5]

Going to take the head off either today or tomorrow. Decided I'll first try and save this engine

Guy at my usual machine shop says he can sell me a brand new head from China, $1850 with my valves fitted.
Anyone heard of or used these? Its non-branded and he says he's been sourcing these heads from a mob in Melbourne for 10 years with no problems...
I'd rather use an AMC head from Turners, but this is about an $800 saving...

[JoeFriend]

Was about to post that if you were in Sydney I have a TD5 engine torn apart now and can likely sell some pieces to you if you need some.

All depends on what avenue you want to take I guess!

[INter674]

Going to take the head off either today or tomorrow. Decided I'll first try and save this engine

Guy at my usual machine shop says he can sell me a brand new head from China, $1850 with my valves fitted.
Anyone heard of or used these? Its non-branded and he says he's been sourcing these heads from a mob in Melbourne for 10 years with no problems...
I'd rather use an AMC head from Turners, but this is about an $800 saving...

Get the head checked first..might be cheaper to rebuild it. ..mine cost 600 for re surface plus new valves n seals etc.

AMC make heads in China n Korea oo...eg Patrol TD42 heads which are fully assembled plus head bolts n VRS gasket set for 1500 delivered on F Bay!!!

We have one here made by AMC in Korea and looks very well made.

Feedback so far is they are okay..stronger than original with bigger cooling galleries and pre comps. New heads no longer available and 2nd hand are mostly cracked non repairable. ..so few options r available for TD42s nowadays.

[Davetd5]

Was about to post that if you were in Sydney I have a TD5 engine torn apart now and can likely sell some pieces to you if you need some.

All depends on what avenue you want to take I guess!

Thanks for the offer, though it doesn't look like I need any 2nd hand parts atm, going with a new head.

[Davetd5]

So it looks like I'm going with a new head and no bottom end work.

My local trustworthy machine shop pressure tested the head and said they found a leak from the coolant passage under the No1 inlet valve seat
So for 1850.00 they sold me one of their new Chinese heads with a combination of my old valves and new LR valves fitted.

As for water damage to the bore,
#1 bore doesn't have the cross hatch pattern as I guess the water has taken that off. The engine guy said from my pictures the surface finish didn't matter, but to look for vertical lines in the bore from overheated pistons nipping up.
There are a few lines in #2 bore, but I suspect that's from when I overheated this in 2010 when the rad by pass hose snapped (which led to the previous time I had this head off at 185,000km).
It doesn't use oil at all even at 320,000 so i'm not going to worry about the bore.

As for a possible bent rod
I checked piston protrusion heights to see if I have a bent #1 rod from hydraulic lockup. Most pistons are consistently 0.37-0.38mm above the deck including No1. The only piston different was #2 which was 0.37mm on the front side but .031mm on the rear side which makes it about 2.5thou difference to the rest. The engine has been running fine it was just losing coolant and hydraulic locking overnight, so I'm gonna say my prayers and take the chance that my rods and bottom end are ok.

So MrsTd5 is out getting some Locitite 518 and I'm about to crawl under the Disco and change the sump gasket and oil pump bolt. Great way to spend annual leave!

[INter674]

Piston protrusion on the TD42 motor we r building atm is measured across the piston not along or front to back. Reason I guess is to eliminated errors from piston lash or wobble.

Your measurement variarions appear good enuf😎

[Davetd5]

Piston protrusion on the TD42 motor we r building atm is measured across the piston not along or front to back. Reason I guess is to eliminated errors from piston lash or wobble.

Your measurement variations appear good enuf😎

Actually I measured across the piston diagonally from 2 O'clock to 8 O'clock because that where the most meat on the deck was

[Davetd5]

So just to finish this thread off.

I fitted the chinese made head and it bolted on just fine.
It ran like a pig at first, but after fitting a long overdue replacement MAF sensor and resetting the cam timing in the correct manner it goes as good now as it ever has. MrsTd5 has gone from being scared it was too slow to being scared that its too fast, so that's a good direction to move in!

You can read about the flat spot and hard starting the improper cam timing caused here:
Td5 Flat spot on take off and hard to start cold since new head fitted (https://www.aulro.com/afvb/discovery-2-a/273593-td5-flat-spot-take-off-hard-start-cold-since-new-head-fitted.html)

Have done about 300kms so far including a short country trip to Goolwa Beach and its all good thus far. No evidence of lack of power from any bent rods so it runs good for something that's done 320,000km and I assume she'll be good now for another 200,000km!
MrsTd5 has already started hunting for a D4 but she'll have to wait it seems.

[Slunnie]

Great news. I also had a cracked head in my Td5 and got it fixed when it was hydraulically locking overnight. New head and away it went also, no bent conrods etc.