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how's about the 3.9l?

frankenstang57

Jedi Warrior
Offline
Question for you guys. I have a Stag with a crappy Buick motor in it. I'd like to swap it for something else. A 302 was my first thought, but the front mounted oil pump kinda bugs me. Locally I've found 2 3.9's in Land Rovers. One is a '91 and the other is an '89 and of unknown mileage. Are these motors worth a darn? Any tell tail signs to run the other way? Do they still use some sort of GM bolt pattern on the bell housing? Thanx!
 

Steve

Moderator
Staff member
Platinum
Country flag
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From what I can gather, the 3.9 seems to be good. It produces 178hp (should be enough) and the only problem that I can find is as follows:-

Hard starting: Difficult starting or a no-start is probably due to a bad ignition coil which has overheated. (The pitch may have even leaked out.) The ignition module is the root cause. (1992-94)

Couldn't find anyting specific to a '91 or earlier. Biggest concern, of course, is how the motor was treated previously. If it's a good 'un then you should be fine. Look for evidence of oil leaks, as there was a problem with rocker cover gaskets at one point.
 

philman

Jedi Knight
Offline
i have a nology ignition system in my rangie, never a problem starting. even if left sitting for a week. No leaks. I had to rebuild the heads, replace the waterpump and radiatior. and I had a problem with the temperature sensor telling me it was running hotter than it was. However, I did drive it from san diego to eugene oregon when i bought it with a blown head gasket (in the summer to boot). and i have found the engine easy to work on and parts easily available. xjs jaguar (a sponsoring vendor) is a good source for parts.

The beat up old rangie has turned out to be the most reliable car I own.
 

DieselBrad673

Member
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Keep in mind some aluminum motors corrode internally,if the anti freeze has been neglected. This engine is lightweight, so it wouldnt make a MGB noseheavy.
 

gjh2007

Jedi Warrior
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I could go on & on about the Rover motor, but the two most important things about them were, they can exhibit a bad head gasket, when in fact the steel sleeve in the cyl block slips & cause compression of the cooling system. Ask me how I know...They are expensive motors to do machine work on. I thought I heard something about the 3.9 late 90's disco motors have some valve issue, but I was running a '88 3.5.

Try this link: Talk to Woody, he is a big time TR8-Rover motor guy..

https://www.thewedgeshop.com/
 

DieselBrad673

Member
Offline
I think in the mid 90s they changed from a 5-bolt head pattern per cylinder to a 4 bolt one as this tended to "bow" the head less.
Smokey Yunick once said "It takes a pound of aluminum to equal a pound of cast iron."
 
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