Newish Jeep Renegade needs new engine

Goudy

You can't completely recondition many newer type engines. They no longer have replaceable cylinder liners or are able to be over bored.

Manufacturers use various coatings and finishings on the bores these days. It's generally referred to as Plasma Coating or PTWA (Plasma Transferred Wire Arc). A low coefficient friction surface is sprayed onto the raw bored cylinder walls in a one piece engine block.

Obviously the finishing has lower friction than a normally sleeved bore but it makes the manufacturing process much cheaper. There is no need for sleeves to be cast, turned down and pressed/shrunk in. They just bore big holes and the coating is applied to the nearest fraction of a micron.

You can of course still rebuild a cylinder head and replace/regrind a crank and replace all the main and big end bearings, but it no longer makes sense if you can't return to pistons/bores to factory spec.

I've ran a few two stroke competition engines in the past where you effectively up size the piston after X hours use, micron by micron. Then when you have run out of piston sizes, you either replace the cylinder completely or have the bore Nikisil treated back to the standard bore (if it's not too over sized or damaged) but generally these engines are typically throwaway now.

Mildly_Miffed

https://forums.moneysavingexpert.com/discussion/comment/81921557#Comment_81921557

…or even simply a good used one out of a write off.

https://www.ebay.co.uk/itm/336176869627
£4.5k for a used engine out of a 2024 4xe, delivered.

Wouldn't surprise me if a bit of phoning round the breaker networks found one in the UK.

But a franchise dealer isn't going to give either of those options. They can't supply ANY parts unless they're from the manufacturer.

Benjie77

This appears to be a very timely thread, as I’m currently dealing with something strikingly similar to CrazyCat.

I won’t bore you with the horrendous customer service we’ve experienced, or how difficult it has been to get any meaningful response from the dealership since the car was transported to them in early February - just the details:

• Jeep Renegade PHEV 1.3 Auto Limited, purchased 01/03/2025 Paid £16.5k. 5 yrs old (2021)
• 12-month warranty taken out (£2,000 cover limit), which states components such as the crankshaft seal were checked prior to sale

• First breakdown (limp mode) – vehicle transported privately to the dealership on 9th February
• Fault identified as auxiliary belt and tensioner
• Dealership did not contact the insurer or pursue a warranty claim as asked/ no one paid.
• Vehicle was returned after repair, although I have no clear record of what work was actually carried out -only a Vehicle Health Check and with quotation

• Second breakdown occurred just 11 days later (going less than 10mph leaving home/ driveway).
• Vehicle transported privately back to the dealership (11th February)
• No meaningful updates or fault confirmation provided to us or the insurer
• Warranty expired 28/02/2026 during this period

We have now finally been informed (24/03/2026) that:

• Engine failure has been diagnosed as a result of a loose crankshaft pulley
• Resulting damage requires a full engine replacement
• Quoted cost: £13.5k (less a 30% goodwill contribution from Jeep (apparently)).

We had started to go through Jeep UK with alll comms but it took a bit of a legal orintated letter on Monday to find out what was going on.

Please let me know your thoughts on this I'm so intriegued as to what has so terably gone wrong since the car was repaired in January.

Do we think the dealership/ garage has a case to anwser, or is this just bad luck - the cars a write-off.

If you're still reading these CrazyCat - what a horrible, horrible situation!!

ThorOdinson

Why do people buy these notoriously !!!!!! cars?

Goudy

I've seen this before, some engines produce odd harmonics on the aux belt system but the crank pulley is damped to remove them. The pulley isn't solid, it's in two halves with rubber between them to smooth out the harmonics.

The rubber eventually wears away and falls apart and the odd harmonics twang the aux belt so badly it can back the bolt out of the crank pulley or snap the aux belt that then snags the crank pulley enough to jam it up. Behind the aux belt crank pulley is the crank pulley for the cam belt, so any problem with jamming can cause the cam belt to jump or snap.

Fords old 2.0 Duratorq was notorious for this, once there was some slack in the dual mass flywheel it sent vibrations back through the crank that actually caused the aux belt twang the tensioner and pulleys until they fell apart. You always knew when one was on it's way out, they hammered like a jack hammer at idle.

There was an uprated pulley kit to helped solve it but really the DMF needed changing as well.

I suspect these suffer something similar as there are a few posts around the internet of similar problems. Some are luck and notice the belt/tensioner is loose or noisy, others not so luck and it fails and writes the engine off.

The actual alternator is a larger alternator/generator for the mild hybrid system, I suspect FPT (Fiat Power Trains who manufacture this engine) have got this arrangement all wrong!

Here's another sad aux belt pulley story.

4XE serpentine belt | Jeep Renegade Forum

and another

Cam belt snapped | Jeep Renegade Forum

daveyjp

https://forums.moneysavingexpert.com/discussion/comment/81937572#Comment_81937572

Because they think its a Jeep, not a Fiat/Peugeot/Citroen/Vauxhall in a different dress.

facade

https://forums.moneysavingexpert.com/discussion/comment/81937859#Comment_81937859

I had an AMC Jeep Cherokee once, that was enough to put me off them for life!

Although I'd definitely have a 1940s MB in good condition if I was offered one at a good price, or won it in a raffle (I tried once, waste of money buying a ticket…)

born_again

https://forums.moneysavingexpert.com/discussion/comment/81937859#Comment_81937859

Stellantis