Thread: D2 V8 Engine: Slipped Liners and Suitability for Towing

Perseverance is your middle name,,

Have you read this?
JE Robison Service — the blog
(scroll down a bit)

Am I right in saying none of the motors had tophats?

IMO the Hi comp 4.6 in a D2 is probably the best tow rig IF you can suck up the fuel bill

With regard to your issues with it, I would say the problem is the factory engine. Get a properly built and engineered top hat liner motor, and you should have no issues. The other BIG factor is fuelling IMO. The Motronic is primarily concerned with economy and emissions, which requires excessive combustion temps. If you were to fit an interrupter type chip etc you can richen the system up somewhat, and you would possibly find no increase in fuel consumption but the engine will run way better.

slipped liners and overheating issues didn't happen all that often back when 14CUX and dare I say SU carbs were about

Just my 2.25c...


JC

Originally Posted by Grumndriva

221,000 km, engine pumped several litres of coolant overboard after a brief run to the shops. Inspection today confirmed a slipped liner in No 6 cylinder. So now I have a decision to make!

Did you have any other cooling system problem or cold start misfire before this happened?

It's just that this doesn't sound like a slipped liner issue as they don't pump coolant out like you've described in my experience.
All the engines I've seen with slipped/porous liners (around 20-30) would have happily continued pottering on for quite a while before becoming a serious problem. In the majority of cases, the owner's only complaint was a cold start misfire when the coolant seeped into the cylinder overnight.

Originally Posted by Scouse

Did you have any other cooling system problem or cold start misfire before this happened?

It's just that this doesn't sound like a slipped liner issue as they don't pump coolant out like you've described in my experience.
All the engines I've seen with slipped/porous liners (around 20-30) would have happily continued pottering on for quite a while before becoming a serious problem. In the majority of cases, the owner's only complaint was a cold start misfire when the coolant seeped into the cylinder overnight.

Hi Scouse,
I only have experience of two, but both of my slipped liner engines acted in an almost identical manner, with both gradually losing small amounts of coolant over a period of time before finally dumping large quantities from the overflow. Neither suffered from rough running on cold starts, but both suffered rough running for a short period on a hot re-start. The current one still runs beautifully once the water in the combustion chamber has gone. The first got progressively worse and then started to make a heavy knocking noise on a cold start for a few seconds, sounding quite like a stuck hydraulic lifter.

In both cases the combustion pressure found any weaknesses in the cooling system and caused minor leaks there, until eventually it just pumped fluid out the overflow after the engines were shut down.

p.s.

After reading the article in Pedro's link it would seem that while we have assumed that the liner had "slipped" in order to account for the lack of combustion gas sealing, the problem is caused by a combination of poor liner sealing design and a small crack in the block. But the end result is the same: massive over-pressurisation by combustion gasses that forces coolant overboard.

Originally Posted by Pedro_The_Swift

Perseverance is your middle name,,

Have you read this?
JE Robison Service — the blog
(scroll down a bit)

Am I right in saying none of the motors had tophats?

Hi Pedro,

I hope that your new D2 is running well for you. No you are right: none of mine had top hat liners. The first was the vehicle's original motor, and the replacements were both factory new engines. I was talked out of fitting a TRS rebuilt 4.6 with top hats by my servicing workshop, who believed that the slipped liner issue was limited to engines built between 1999 and 2001, and that a 2002 or later engine would be fine. Sadly they were wrong. If I decide to keep this one (and it is a great vehicle in all other respects and well set up), I will have the current engine rebuilt with top hats as long as the block is still OK, which the original was not.

p.s.

Thanks for the link. Very interesting and his thesis sounds logical. It also gives me some hope that this engine might be perfectly repairable with top hat liners.

Originally Posted by justinc

IMO the Hi comp 4.6 in a D2 is probably the best tow rig IF you can suck up the fuel bill

With regard to your issues with it, I would say the problem is the factory engine. Get a properly built and engineered top hat liner motor, and you should have no issues. The other BIG factor is fuelling IMO. The Motronic is primarily concerned with economy and emissions, which requires excessive combustion temps. If you were to fit an interrupter type chip etc you can richen the system up somewhat, and you would possibly find no increase in fuel consumption but the engine will run way better.

slipped liners and overheating issues didn't happen all that often back when 14CUX and dare I say SU carbs were about

Just my 2.25c...

JC

Hi Justin,

Thanks for that. I agree that the engine, when it is working, is a good towing motor. It is just that Land Rover didn't build them to last, but I take your point about a properly built and engineered one.

Mine is not that bad a fuel soak: I get around 24-28 LHK, depending on wind, while towing the van which is pretty tall and heavy. This is pretty much the same as the Land Cruiser doing the same job. Thank goodness for long range tanks though!

I had always thought that mine ran a bit rich, since there has always been a bit of soot around the end of the exhaust. If I keep it, I will investigate the chip option.

I am glad to see your new middle name is warranted

P38arover has had his 4.6 tophatted(?)and seems to be pleased,,

while that robinson blog might explain why,, (interesting that rover changed processes so that the liners cant move--)
he doesnt fix the new problem,,

IF I had to do this, (touches head) I would pick an earlier block and tophat it,,, maybe the extra machining involved in the newer ones weakened the head bolt surrounds?? JC ?

I also think( and all this is a just backyard mechanic thinking aloud Grumn) that lowering the operating temp just a few degrees might help in general, there isnt much between operating and boil in a D2 V8,,,

Has anyone else ever opened the bonnet on a D2 V8, in front of a NON LR mech, to be met with crys of
"ITS TOO HOT! thats your problem!"

after all the above if you are still with us Grumndriva,, tophat it.

Good Luck.

Yeah, still here Pedro. The car is just too damn good for everyday use to get rid of it IF the top hat liners will fix the problem permanently, as Robison claims.

I keep looking at the D4 and LC200, but I have doubts about the former's suitability for bush road towing, even when modified, and the latter is too big for my everyday use, and the Patrol can't legally pull my van (at least not in auto form). The D2 is still the best all-round compromise IF I can have confidence in the engine.