Swapping petrol engine out for a diesel

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_LostLocal
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Joined: Fri Oct 27, 2017 11:54 pm

Swapping petrol engine out for a diesel

Post by _LostLocal »

Hi guys, so I'm new here and im not sure what forum I should put this in so I've just put it in the genral chat.

I've owned a cavalier before and loved it (unfortunatly I had to sell because I could not afford the fuel it took.)

Anyway, I am now after another one but I am very picky...
Im wanting a Diesel, Green Saloon.... not easy to find.

So I was wondering how hard it would be to convert a petrol to a diesel, and what engine/gearbox you would use?

Thank you in advance
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Cavalier342
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Re: Swapping petrol engine out for a diesel

Post by Cavalier342 »

Welcome to the forum. Usually folks tend to to it the other way around, although the Isuzu 1.7td engines are supposedly well proven and tough as nails, not sure how easy it would be to find a good engine nowadays, as most Cavaliers have petrol engines nowadays.

There are members here who know exactly what is required to do so, I mean as for basics, you're talking a replacement engine, ECU, wiring loom, glow plug relay, with regard to gearboxes, I don't know which gearboxes were fitted to the diesel models, could be an F16, or an F18, I assume close ratio, and perhaps the engine mounts are different, I'm not too sure.

Hopefully someone will shed some light onto this thread for you.

I've owned two 1.8 petrols and a 2.5 V6, and to be honest the 1.8s aren't bad on mpg as long as you don't thrash them, but these days I think most drivers spend more time idling in traffic jams rather than cruising, so it doesn't make much sense to me to own a diesel, unless you live somewhere rural with little traffic to worry about.

Regards.
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Robsey
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Re: Swapping petrol engine out for a diesel

Post by Robsey »

I would suspect it is quite an involved process requiring all the following.

1 - Engine, ECU and loom.
2 - Engine bay electrics / loom
3 - Interior wiring harness due to changes in clocks, relay and fuses.
4 - Diesel fuel tank and possibly fuel lines.

In my own situation - I would only entertain such a huge conversion if I had a complete donor diesel Cavalier with a rotted out shell, and worn out engine in my current Cavalier.

The economy in the TD is very good and far superior to any petrol engine, but only worth pursuing if you have a lot of time, confidence and all the necessary parts to do the conversion. Oh and decent work space / location and tools.
Not ideal out on the drive.

The money spent on converting would probably be more than the difference in fueling costs.

Sorry if I sound negative - It is more open minded caution.
Be a nice project though if you decide to press ahead with it.

As for durability - I think that the 2 litre 8 valve engines are potentially just as tough as a diesel. Just not as economical.
Approx 30 to 32 mpg combined cycle.
(Urban and motorway).
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Robsey
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Re: Swapping petrol engine out for a diesel

Post by Robsey »

As for diesel engines...
There are probably plenty of non-turbo astras about, as the 17d was commonly fitted to the vans and estates.

The non- turbos are much more sluggish, but upto the job if you are not in a hurry.

You could consider a Vectra-b diesel, as I assume that all these will be turbos and most wiring will be very similar - same can be said for gearboxes. Both the Astra and Vectra-B mounts will be different but not so different that Cav mounts cannot be fitted. The differences will mainly be due to inner wing / chassis shape and dimensions.
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James McGrath
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Re: Swapping petrol engine out for a diesel

Post by James McGrath »

I wouldn't have thought that a green TD would be that hard to find to be honest.

You're probably going to spend more time on the conversion than you would if you just waited for one to come up for sale.
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