I am shopping for a used Disco after being out of the ownership world for a couple years. I previously had an '04 and used nothing but premium gas. I just test drove an '02 SD with 99,000 miles which seemed very mechanically sound and I think I am inclined to make an offer. The current owner has had the vehicle 10 years and states he has only used regular gas. With this being the case, are there specific problems/symptoms due to using the wrong grade gas over that period that I should be on the lookout for?

Thanks!

 

i wouldnt go near that poop box. after 10 years that has got to be some serious issues. the knock sensor has worked overtime in that truck... newer engines especially those with turbos can compensate for the lower octane, but our old designs don't bode so well with long term low grade gas. i would keep looking.

 

You will probably be looking at early head work from carbon build ups from low octane.
What is he asking for this Disco?

 

Yea its not the end if the world especially if the head gaskets have not been done yet. You will have the heads off anyways. if its a good price and in good shape i would probably do it. How many miles also sounds like he has had it for a long time and would know the history.

 

Poor concept of octane rating and compression?

1st no knock sensors don't "work overtime" and even if they did. That too would not cause excess wear.

2nd these engines are low compression

3rd no the cylinders don't run "extra hot"


That disco would be just as good as any other.

 

The asking price is 4500, I'm offering 3000. Head gaskets have been replaced.

 

One idea is that lower octane gas washes down the cylinder walls, rather than burning off as cleanly. And this finds it way into the oil, and is part of the sludge formula. But don't let keep you from negotiating a good price.

 

Sorry but Ihave seen them like that ran "always using premium" I have also seen them clean "always using regular" so it'll take alot more convincing.

But why would regular run down cylinder walls and not premium? Spay pattern should be the same, only thing I see is the premium being LESS likely to combust, giving it more of a chance to do this.

 

Exactly! It's still shocking to me how this remains such a prevalent myth in the auto-industry when it comes to older low-compression vehicles.

I had a stock 300hp mustang rated at regular 87 octane gas and have seen that modular V8 CLEAN AS A WHISTLE running that fuel. I've also seen high-end european S50/S52 M3 engines from friends with 200k miles on them that looked just as dirty as the heads pictured above running 93 octane for 17 years.

Honestly it's a little shocking that an ~8:1 CR engine requires premium fuel when my friends 11:1 5.0 'stang without direct injection still runs on 87 and makes 400+ hp stock.

I run my rover on 87 all day long and she's happy (relatively, lol) for a 1.5 decade-old engine with 190k miles on it! FWIW I get worse econ on 93.

 

are you saying that knock sensors have nothing to do with the octane gas that you put in the fuel tank? Because that's just retarded. and for your last 2. I never said the engines were high compression and I never said they run extra hot so what the hell are you quoting? good luck with the **** you dump in your tank thank God I'm not the sorry sack to buy your hunk of s*** when you're done with it