What exactly is the problem with VM Motori engines?

[Francois Theron]

As a complete Jeep ignoramus, I would like to know what exactly goes wrong/is wrong with VM Motori engines.

These things are fitted to many vehicles, but generally when they are mentioned on any forum, the feedback is fairly negative.

I would really appreciate some solid, technical feedback from people in the know. Not anecdotal hearsay please.

Lets see what comes up

[Quiksilver]

Well...in the Jeeps there was the 3,1 in the WJ. This was a ##### engine, prone to overheating and just generally problematic.

The 2,8 in the KJ and JK's where ok. JK's seem to suffer more issues, my gut is because the vehicles are used harder, modified more etc.

Basically though, Jeep doesn't focus much on diesels, so they are always added as an afterthought into the range and almost always on international models only. Then I think a lot of dealerships (at least early on) didn't know how to service them properly. Plus they have a 20 000km service interval which is crazy.

The new one in the WKII seems to be really good. Thats the first Jeep with Fiat input, and I would hazard they have more diesel experience than the Americans.

Other notable diesels where the 2,7 merc unit in the WJ, and the excellent 3,0 Merc unit in the WK.

EDIT: Personally, I think the EGR system on all these models are a problem and should be disabled asap.

[jelo]

Various models of the engine have been used by Land Rover and Jeep and Chrysler.

Consensus amongst most owners of the Jeep Cherokee XJ, the GC ZJ I think and the Range Rover classic are that the 425OHV engine (2.5 L (2,499 cc or 152.5 cu in) I4, with two (pushrod-actuated) valves-per-cylinder and indirect fuel injection) was a horrid piece of shite.

Land Rover dropped the engine for the 300TDi as soon as they could. Jeep unfortunately had no such epiphany.

The R425DOHC and R428DOHC are just later mutations of this POS with a different cylinder head and direct injection.

The 3.1 was an R425OHV with an extra cylinder, hence the bad genetics.

The latest A428DOHC appears to be a better animal.

[XJ Junkie]

Jeep have always been behind when it comes to diesel engines, in fact, I don't think they have ever made one under their own brand. In the USA their focus has always been on petrol engines, especially big ones. Fuel is cheaper in the USA which is where the bulk of all Jeeps are sold. Interestingly, there have been many Jeep diesels available in other countries that were never available in the USA, including the Wrangler.

But Jeep needed to sell more vehicles in diesel loving countries but they didn't have engines, so they bought motors from VM Motori. The ones they bought were effectively Italian boat engines. Its a funny engine with 4 separate heads on the 2.5 & 5 on the 3.1. Last time I heard the price it was something like R18k per head.

Whilst the VM's were fine in Europe, they are no good in our hot SA climate. A non-turbo variant of the 2.5 was actually used very successfully in the older London Taxi's & could clock up serious mileage, but probably had help from the cold weather. VM even supplied Range Rover.

Since Fiat bought VM they have made some brilliant engines, like the 3.0 V6 in the latest Grand Cherokee & Maserati. Its even better than the Merc V6 that it replaced.

But old Jeeps with VM motors are really, really, really bad

[Francois Theron]

Guys, thanks for the responses, but I'm no clearer on the subject. Calling an engine all sort of names still does not provide an answer to my question. What is/are wrong with these engines?

Are the blocks weak, do the cylinder heads crack, do they use oil or what? Bad dealerships do not give you bad engines although it can give a good engine a bad name over time due to bad service.

What is it that goes wrong with these engines that give them a bad reputation? Overheating was mentioned, but was that the engine or the cooling system designed around the engine?

I get the feeling that these engines have been built as general use units and then fitted to various vehicles, so it was never desinged for any specific vehicle, or am I wrong?

[Francois Theron]

OK XJ we posted at the same time. That clears it up for me a bit more, thanks

[jelo]

As XJ Junkie alluded, it was a combination of bad head design, inefficient cooling systems and a badly applied turbo upgrade.

Land Rover had the same issues with a similar generation engine: they took the 2.25 diesel engine, bored and stroked it to 2.5D, and it behaved OK.

As soon as they added a turbo, it was a disaster. The pistons were too weak, there were no oil jets for the piston crowns, and the heads couldn't handle the high EGT from the turbo.

Some engines are just crap.

[XJ Junkie]

Crappy heads, crappy plumbing, crappy viscous, crappy overall design. Even the temp gauge sender was highly inaccurate.

VM used to be owned by the Italian government so it was designed & built by communists .

[XJ Junkie]

VM is to Jeep, what the KZTE is to Toyota & what the 2.0 will be to Amarok.

[jelo]

VM is to Jeep, what the KZTE is to Toyota & what the 2.0 will be to Amarok.

And what TDV6 is to Land Rover

[XJ Junkie]

And what TDV6 is to Land Rover

I didn't forgot about that particular one, its just too sensitive to mention

[Henris]

VM is to Jeep, what the KZTE is to Toyota & what the 2.0 will be to Amarok.

We are the only ones that really make the KZ work this hard, but the cooler thermostat has by and large, sorted this problem.

Is something like that not a remedy for these VM engines?

[XJ Junkie]

Is something like that not a remedy for these VM engines?

Apparently the engine blocks make very good boat anchors

[JacoE]

& what the 2.0 will be to Amarok.

Eina

Is this not the same 2.8 that goes in the Chev TB?

[Francois Theron]

VM is to Jeep, what the KZTE is to Toyota & what the 2.0 will be to Amarok.

I'll happily buy any one of the two. The KZ can be made to last and the 2l in the Amarok has proven itself by now IMO.

From what you guy's have said here the VM is not even comparable to these two and there is no cure to make it last. The same seems to go for the LR V6 diesel, its hit or miss.

[jelo]

I'll happily buy any one of the two. The KZ can be made to last and the 2l in the Amarok has proven itself by now IMO.

From what you guy's have said here the VM is not even comparable to these two and there is no cure to make it last. The same seems to go for the LR V6 diesel, its hit or miss.

I'd rather take a 3.0L 3000D 5L. And you are too biased on VW products to be believed on the second one.

[Henris]

I'd rather take a 3.0L 3000D 5L. And you are too biased on VW products to be believed on the second one.

Nobody runs a NA diesel anymore. And the 5L with a turbo, is just a disaster. Period.

[XJ Junkie]

the 2l in the Amarok has proven itself by now IMO.

Have you noticed how all the high mileage ones don't get thrashed offroad by their owners?

There is something suspicious about an engine that has mounting brackets for an engine cover, but the manufacturer later elected not to fit one.

Then they took the low range & proper reverse gear away in order to limit its overall use. Maybe to prolong the engine?

[jelo]

Nobody runs a NA diesel anymore. And the 5L with a turbo, is just a disaster. Period.

I see more 3000D's on the road than KZ-TE's

And I never mentioned a turbo

[Francois Theron]

Have you noticed how all the high mileage ones don't get thrashed offroad by their owners?

There is something suspicious about an engine that has mounting brackets for an engine cover, but the manufacturer later elected not to fit one.

Then they took the low range & proper reverse gear away in order to limit its overall use. Maybe to prolong the engine?

I have enough personal experience with the 2l VW diesel engine and more specific in the Amarok not to worry about it. Unlike some people who are very vocal about it but has probably never even been inside an Amarok.

As for the engine cover which you seem to be so hung up about. What exactly is the idea of that cover?