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Engine rebuild/replace advise needed.

10K views 104 replies 23 participants last post by  cgalpin 
#1 ·
I have read a few threads on this, but since things change over time, I'm going to have to ask..

My engine started a scary sounding knocking noise after what seemed to be an overheating (without the gauge going over the middle so my e-fans didn't kick in - was low on coolent though). As soon as the engine warmed up, the noise would start - you hear it at idle, and then it quietens as soon as you rev it up a little.

I took it to a local shop who does deal with rovers, but am not 100% how much. I talked to a front desk guy who said after pulling a valve cover to look, they were looking into what options to recommend me so didn't have a quote for me yet and was also a bit vague on the details, but said I have a worn camshaft and rockers. Seemed to indicate the work needed was extensive enough to consider replacing over repairing/rebuilding. Engine has under 90K on it, but seemed to overheat easily. Other than that it ran fine.

Ok, I guess my questions are two fold.

1. What questions should I be asking the shop to determine the true extent of my problem. It's not that I don't trust them, but want to fully understand the scope of this once I talk to the mechanic.

2. Assuming it's in bad shape, what options would you recommend? I am in no position to do this myself right now (although I'd love to), so thats out. I'm obviously sensitive to price, but would like to make the move that will give me the most longevity and reliability as I can going forward. I have read that rebuilding using a 4.2 or 4.6 block is better and doesn't cost much more, etc. Also is it really that much more expensive to buy a rebuilt engine than to have mine rebuilt? I'd assume having the actually rebuild work done by a shop that does rover work all the time would be best, but I really don't know.

Any and all advise would be appreciated.

thanks
charles
 
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#2 ·
I know very little of engine mechanics, so this is just a "conceptual" thought...

my neighbor replaced his head gasket, and while at it did the camshaft... he ended up putting several hundred in parts into it over the course of a few weekends (it's a spare vehicle, no rush). He got it started and it runs very well.

If you read my posts, you'll see I get news like that and panic... then after seeing what's going on, ti seems I realize I can/will figure it out. I'm not saying do the work yourself; in my long-winded way, I'm saying wait until they very specifically tell you why you need a new engine. And then get second opinion(s).
 
#3 ·
Well, a cam, lifters and gasket set would be cheap, but with that mileage you really should replace the main bearings, and have the heads pressure tested b/c of the overheat. Its really up to you, you should be able to have it rebuilt relatively inexpensively by a good machine shop, but you still have to pay to have it pulled and replaced if you can't do that yourself. It will probably be cheaper than buying a rebuilt, but the real decision is whether it is worth a little more to upgrade to a 4.6 or a diesel etc. You have to really consider your options and what makes the most sense to you. Check with Pendy...he can probably help guide you in the right direction.
 
#4 ·
I would do a compression/leak down test. If that came out fine than I'd pull the heads and check the head gasket. If the gaskets are fine than I'd opt to drop in a new block. I'd have to make sure it wasn't just a head gasket issue. If the issue is in the crankcase, rods or piston rings i'd definately find a new block rather than fiddle with a used one (unless I was willing to take the risk of wasting money on a bad ie porous block

Neil
 
#6 ·
Stmpede said:
Well, a cam, lifters and gasket set would be cheap, but with that mileage you really should replace the main bearings, and have the heads pressure tested b/c of the overheat.
Is that because the engine would be rebuilt and this is worth it or do they really wear that fast? I thought the 3.9L would last at least 250K without major maintenance (under "normal" condition).
 
#7 ·
Well, when doing rear mains I have noticed that around 100k these engines are usually showing the brass on the mains. When doing a rear main we just put em back together, but if you are doing a cam, lifters etc I think it is worth just doing it all and knowing you are good for another 100k. Also, if the cam is excessively worn it may be due to oil starvation from a bad pump, or PO not changing the oil etc. Either way, if some parts are overly worn from oil starvation I would be pretty skeptical of the mains too.
 
#10 ·
High Tech Auto and truck in chantilly. Trying to not look impatient, so waiting to hear back from them still.

Thanks for the advise guys. Once I get some info on what's wrong, I'll report back.

I'd like nothing more than to go diesel, but fully expect it to be out of my budget. I'll do some research though.

charles
 
#13 ·
Just as an FYI, I read this on the discoweb.org web site (extract from a thread where someone is asking how to get more power from a '95 Disco 3.9L engine):
==========================
At 135K, the cam will be showing some wear, there are probably a hundred sub $150 choices for a new one. A new cam, inexpensive lifters, a chain and sprockets will restore what it had when new and then some. For under $500 and a good Saturday, it's the cheapest power you will ever get out of this engine.
==========================
So make _sure_ the problem is really the worn cam, no one mention any noise.
 
#14 ·
Another copy-paste from Discoweb regarding an engine problem (DII though, so... different engine?):
============
Heads rattle like dice in a cup (rocker arms, I'm told)
============
 
#15 ·
Yeah, rocker arms are a common problem. The funny thing is he mentions excessive wear on the cam and lifters only a week after a tech was showing me a DII cam he removed where one lobe was almost round and one bearing journal was destroyed. The engine came in missing and he couldn't figure it out right away. Fortunately that one is still in warranty though, so he just ordered a new shortblock through rover. I have never seen excessive wear on a single lobe and journal though...must have been a blocked oil passage or something...
 
#16 · (Edited)
It's funny you say that, but to my untrained ear it sounded like it was just one lobe/lifter on mine too. A blocked oil passage might explain it. Still waiting for info, but realized it's past closing time, so I guess I'll be calling on monday.

As an aside, how bad of an idea would it be do drive it like this? I'm pondering my options for taking it for second and third opinions and wonder if I can risk driving it like this.

Tony, do I hear you volunteering to come out to the 'burbs to help me work on this pig?

charles
 
#18 ·
Charles, once you find out a little more about your current motor status, I would get in touch with Will Tillery. He's putting a 4.6 into his own D-90 I believe, but you could always source another 4.0 to keep it cheaper. Since you're in VA, I would seriously consider shipping the truck to Will in Danville(probably less than $250!) and you'll get a thorough job done at better rates than NoVa! Just something to consider...
 
#19 ·
Thanks Tony.

JB, I'll certainly look into that, thanks.

Still don't have the details but I swung by the shop yesterday evening to peek at it and caught the front desk guy. I got the same vagueness from him, but did find out who had been looking at it and will ask for him monday morning. They clearly wont be a good option for the work - he mentioned getting a rebuilt motor from AB for $9k, or 33 hours of labor (at $100/hr) for a rebuild (not sure exactly what though and then of course you'd have all the parts ad machine shop on top of that I assume).

I'll buy an old jeep for the summer and fix it at my own pace before paying those kind of rates I think :)

charles
 
#20 ·
Agreed on sourcing a motor from Will, but I'd put some work into the existing one first. It just seems odd that at that mileage a motor that's been maintained and didn't suffer multiple or catastrophic overheating would go south. I sure as hell wouldn't spend $12K at a shop that may or may not know what they're doing, though. Loic may well be on to something with a bad rocker assembly to start. If it were me, I'd get a second opinion from Trevor or maybe that airpark rover place in Gaithursburg and see what thier thoughts are. From there we can start turning a wrench or two.
 
#21 · (Edited)
Put a 4.6 or 4.2 lower in your 3.9 with a cam & some porting & a balance job & youll have some NICE power

Try some marvel mystery oil in the cc if that quiets it down your ok. 90k is not that many miles if you have taken any sort of care.

build another engine & drive it till it puks!


Will is a great guy but why not build what you want get a block from D&D 500$ put the **** in it you want its not rocket science..
 
#22 ·
Just an FYI Trevor isn't with Treasured anymore. He's got his own shop in Elizabethtown PA. About 2.5 hours from me. His email is trevor@roverlab.com Btw let me know if you need help.
 
#24 ·
loose sleeves?

If your engine overheated, it is also possible the cylinder liners came loose, and are moving up and down slightly with the piston as the engine runs. The cylinder liners are basically pipes made out of steel pressed into the aluminum block at time of manufacture. Rover tolerances being what they are, the liners on many engines weren't well seated (engine machining shavings, etc in the way). So when it overheats, it comes loose and gets only worse with time; it's called a "dropped liner." Notorious rover engine problem. Basically, any competent auto machine shop can pull out the old liners and press in slightly larger ones. Don't know the cost.
 
#25 ·
Not to be a contrarion, but I'd be amazed if he'd dropped a liner on a 3.9 with low miles and good maintainence. A 4.0 with 150K with infrequent oil changes, sure, but these are strong motors. My gut says that a head job will resolve this. Hell, we couldn't even hear the knock the other night! Granted, it is a rover, so all bets are off the table. . .
 
#26 ·
CaptMidnite said:
If your engine overheated, it is also possible the cylinder liners came loose, and are moving up and down slightly with the piston as the engine runs. The cylinder liners are basically pipes made out of steel pressed into the aluminum block at time of manufacture. Rover tolerances being what they are, the liners on many engines weren't well seated (engine machining shavings, etc in the way). So when it overheats, it comes loose and gets only worse with time; it's called a "dropped liner." Notorious rover engine problem. Basically, any competent auto machine shop can pull out the old liners and press in slightly larger ones. Don't know the cost.

I have tried to press these out & its not an easy thing. If you get it out then what are you gonna put in??
 
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