I bought this 1995 Montero SR. The previous owner said the timing belt was replaced recently (no receipts). I don't really trust the guy. Sooo....

If the timing belt breaks... Will the lower end of the motor pistons/rings be damaged? I know the valves would get destroyed and heads would need to be rebuilt. <img src="/forums/images/graemlins/scared.gif" alt="" />

If the butterfly valve breaks... How much of the engine will be damaged?

Thanks for your input. <img src="/forums/images/graemlins/kewl.gif" alt="" />

-Peter

It's certainly possible. The pistons may hit the valves on their compression stroke.

As for the butterfly valves, I've always heard...

Bad things can definitely happen. First they will fall into your intake manifold. If they don't get hung up there, the next stop may be one of your cylinders where the parts that fall in will likely stay until you remove them.

Loose parts in your intake and cylinders is a recipe for disaster IMHO but then again IIWY, I'd wait to hear what some of the other more technical forum members will say. <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" />

Where did you order your suspension lift from?

Originally Valley Springs. But... After further research I canceled my spring order. They fixed the sagging issue but in trade limited the coil flexibility. I think it's a good spring solution for on road and increasing ride height.

I'm working with Coil Spring Specialties now. They designed springs for me 7 years ago for my 1992 Montero. I drove it off road for over 2 years without any sagging or other issues.

The springs will be a progressive rate coil based on the stock spring rate but able to carry higher load (extra 500 lbs) and 2.5" higher ride height. Their initial quote was under $300 /pair. <img src="/forums/images/graemlins/smile.gif" alt="" />

OME is a good option but $150 + Shipping for 1" height increase is silly. I haven't found any other options.

Thanks for your response.

I had a 2000 Montero Sport that had the timing belt break. It just needed the heads done (lower end was fine). 3.5L SOHC

How much damage could butterfly valve pieces in the cylinders create?

it really depends on the rpms that it breaks at. I've seen a 4g63 at the jyard, 3 ppistons with holes, only 2 valves somehow werentscrewed up. number 3 cyliunder had valves imbedded into the head, and number 4 was the only piston that didnt have a hole in it.if you are worried then just change it. Pop the timing cover off and look at the belt tos ee if it looks fresh.

I think the DOHC is in 1995 SR Not SOHC right? If belt breaks it would be devastating. Don't know much about Butterfly valves-but they have always scared me <img src="/forums/images/graemlins/scared.gif" alt="" />

Timing belt breaks: worse case you have a bunch of bent valves, a few pistons with major damage, maybe even more collateral damage to the valve train in the heads.

Butterfly valves: worse case you have scored cylinder walls, broken rings, piston damage.

Either way you are talking a lot of $$$ and time to fix the worse case.

I would take the engine down to the timing belt assembly and inspect the belt, check for proper tension, inspect the water pump seals.

Do a search on the butterfly valves, I seem to remember some one mentioning that they tick or chatter before they let go. I chose to just replace the lower plenum when I bought my used 95 SR so I haven't heard it myself.

Thanks for the information. I'll pull of the timing cover to check on the T belt. And I'm going to plan on doing the lower plenum and valve stem seals later this year.

Has anyone done the valve stem seals on 24v motor?

You really aren't going to be able to tell much about the age of the timing belt with a visual inspection - unless it has started to come apart already which means you're going to have to replace it immediately. My experience has been that a used timing belt looks pretty similar to a new timing belt, and there's no way to know whether the one on your vehicle has 5000 miles or 50,000 miles on it.

The butterfly valve problem originates when the bushings that support the butterfly valve shaft wear out, allowing the shaft to move around and vibrate. This vibration and movement allows the screws holding the butterfly valves to the shaft to possibly loosen and eventually come out, dropping into your intake, along with the valve itself eventually. You can check to see if your shaft has any play in it - you'll have to remove the bracket above the thermostat housing to see it. Get a screwdriver down in there and see if you can move the shaft up and down or side to side - if you can then you need to replace your lower manifold assembly. Not only is there a possibility of the butterfly valves coming loose, but you'll have a vacuum leak also that can affect how your engine runs.

Looking at the front of the lower intake manifold with the bracket removed - the actuator moves the actuator rod which moves the bellcrank on the end of the shaft.


Another view from the side - you're looking for the white spacer behind the bellcrank, that's the end of the shaft.


Another view, lower manifold assembly off the vehicle.