Loud knocking, shaking, then died on hwy...

[jpk503]

I'll preface this by saying that I'm not all the savvy when it comes to understanding/troubleshooting issues with my '87 deli but I've done some repairs and have enjoyed learning through each. With that said, I'm looking for some help on where to start with this one.

I've noticed over the last few weeks that the engine sounds like it's working harder. It's hard to describe but noticeable more on the highway - running louder, more pronounced diesel knocking sound. Anyways, I was driving over the mountain and monitoring my EGT, generally taking it slow. 15 miles after going over the pass (flat road) I noticed the engine was pretty loud and then it started running really rough - shaking, loud knocking and I could hear the fan hitting. I was going about 90km and I immediately put it into neutral, which quieted everything down and started to pull off. I put it back in gear to help slow down and it ran rough again and then died before I could pull all the way to the shoulder. I gave it a second then tried to start it but it wouldn't turn over and would puff a cloud of black smoke with each attempt. No other smoke was noticeable in this entire ordeal.

I got it towed back into town 2 hours later and tried to start it again. It puffed black smoke and started on the first attempt but ran pretty rough. Not as rough as when I was on the highway but sort of rough like a cold start.

That's where I'm at. Initial thoughts? What would be a good checklist to work through? Thanks in advance!

john

[Big-Bird]

You said you heard the fan hitting?

sounds like the crankshaft pulley broke which is common.

The crank pulley smooths out engine vibrations with its heavy weight but the rubber liner that joins the inner and out steel parts of the pulley gets weak and the outer part) starts to move towards the radiator and makes contact with the fan.

vibrations are quiet at idle but as the RPMs pick up the big pulley can't do its job and the noise/vibrations turns into what you described

the crank pulley is an easy repair and even easier to verify if its wrecked. Crawl on your back and look at the bottom most pulley.

the pulley is reasonably priced but their might be some crank shaft bore variations so you will likely need to provide some engine data to the Vancouver JDM parts guys. of there is someone on the forum who has the same van as you they might be able to help with an eBay or other online purchase which would be cheaper.....the risk is it may not fit your van.

[jpk503]

Great, that's where I'll start! I'm planning on getting the van back to my house tomorrow so I'll report back then. Thanks!

[jpk503]

I checked out the pulley and it seems alright. It's tight and there doesn't seem to be any damage. Belts are relatively tight as well. See pics.

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[Big-Bird]

From your pics the pulley seems to be in the right place.

Loosen the belts and check that crank pulley with no tension on it. Put a prybar/long screwdriver between the pulley and the engine to test for excessive flex in the pulley. Don't go superman on the thing...gentle prying will tell you if the pulley is wrecked or not.

Is your EGR valve connected ? When its working normally the engine runs well but when they fail the engine runs awful and will often quit at idle.....they pop, fart, puff gobs of grey, white and black smoke.

Covering the ports with thin metal plates to block the EGR is one fix, pulling (and blocking) the vacuum line that activates the EGR is another method.

If all of this still proves no-dice then your motor may have internal problems which needs proper diagnosis by a tech who knows diesels. If you know of any tech's who work on small tracked Caterpillar equipment in your area chances are they have seen the MItsu Diesel engines....and by small I mean fit in your back yard to dig a narrow trench kinda small.

[Growlerbearnz]

I wonder if your timing belt has slipped a tooth? (or two).

[jpk503]

Thanks all for the continued feedback. I'll probably just pull off the pulley and inspect it to rule it out either way.

I have an EGR blanking plate but I'll check to make sure that it's all tight.

If both of those prove to be alright, I'll have to dig into the timing belt.

Unfortunately I'm tied up for the next few days but hoping to have some time late in the week to dive in. More to come.

[jpk503]

I was able to loosen the belts and check the pulley and it's as tight as can be. No wobble or looseness. To that end, all the belts and pulleys are tight. I also pulled off the timing belt cover to check the timing marks but turns out the marker piece is missing, broken off or something. See the photo. It's generally pretty close though.

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After that, I had a mechanic (who has worked on a friend's Delica) come by and we checked the heads (good) and looked for metal shards in the oil, but found none.

Before draining the oil we ran the engine for a bit and he's confident that at least one of the cylinders is not firing. Below is a video. He thought it was initially a rod or crank bearing but since we didn't find any metal in the oil, he ruled that out. We are basically at a point where he says something is wrong but he has no idea what it is.

https://youtu.be/dD1Ot_zKT18
- it was a cold start so I'm giving it a bit of gas, then let off to idle

What we've ruled out or know:
- pulleys are good
- noise is not under valve cover
- no chunks of metal in the oil
- EGR blanking plate is fine

I'm going to get a compression tool (his recommendation) and test the compression. Any other ideas?

[Big-Bird]

That runs horribly! Is it getting enough fuel?

Plugged/fouled injector(s)
Fuel pump timing may have jumped a tooth which can happen when the engine gets a upset of power.
Did your.mechanic friend pull the valve cover off and turn the engine over by hand to watch the valves open/close fully.

[jpk503]

Thanks for the feedback.

We did turn the crank and watch the valves and beside them needing to be adjusted, everything looked fine and turned as it should.

I'll look at the pump timing, any recommendations on how to clean/check the actual injectors?

[Big-Bird]

Removal of the injector is easy enough but you need to bleed system pressure before you open them. The only way to test an injector is a bench test which would allow you to see the spray pattern at the tip.


check your fuel pump timing first. Being in the US so far away from good techs must be a challenge.....I would like growlerbearNZ to chime in too.....he knows these engines well.

[jpk503]

I think the timing is alright. See photos of all the marks.

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I'm going to try and find a diesel specialist that can assist in removing/testing the injectors next.

[RickJ]

While it could be a timing issue due to a slipped belt (and we cannot tell due to the fact the pointer is missing), what I would do first is start it and while it is idling, crack open each injector pipe at the injector top one at a time. If it is an injector, issue when you find the faulty fellow the engine will not change in the way it is running. be prepared for it to stall a few times while doing this as it could be running on only 3 cylinders at the moment, it probably wont want to run on 2. The one (or more) that dont cause a change in the running should lead you to culprit.

[RickJ]

Here is a link to a video which shows as I was describing..

https://www.youtube.com/watch?v=aJAZvqQp0KY

[Growlerbearnz]

Your camshaft is one tooth off in that photo- the timing mark (if it was there) would be pointing at the next tooth down:

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The injector pump timing looks perfect.

Also, in the video, it looks like the timing belt is moving around a lot, like it was a bit loose. It's probably just YouTube's motion stabiliser trying to be helpful, but that top run of timing belt shouldn't flex hardly at all- there's going to be some vibration, but it should only be about a quarter inch. Of course with the engine running that badly the belt's going to be under a lot of stress.

To be safe, I'd be replacing the belts and tensioners, because they've been stressed.