Engine suddenly quit.

[Jedidiahwiebe]

Was driving along everything running smoothly. One might say: "running like a top" as it was running fine until it suddenly stopped. Was going at about 20km/hr just pulling out of an intersection. It started to sound wrong the split second before it died.. Like kind of a whump whump sound.

Whumping sound continues when I try and crank it over. Fuel is getting to the injectors, I cracked them and they spurt pretty good. Too bad it's WVO though... That will be annoying to start up when it gets cold.

Fluids are fine, and it's getting fuel. Was running good until the second it died. I'm thinking timing belt jumped? What else should I check?

The belt has around 30 thousand on it. I replaced it myself along with all tensioners, water pump and seals. Sooo it seems ridiculous that the belt would fry at this stage, but who knows maybe I didn't tension it right? I'm just a redneck after all.

I'm going to try and get 'er home and verify that the timing marks are lined up.

Any suggestions?

[Jedidiahwiebe]

I'm opening it up right now. Looks like the balancer belt fell off. Hopefully that's all!

[thedjjack]

it will run fine without the balance belt....

Unfortunately, the balance belt might have taken out the timing belt or it got under it and made it skip...

turn it over by hand slowly and check the timing lines... piston hitting the valves is likely...

also, pull the valve cover and check for valves stuck down or damage to the rockers...

did you do the balance belt at the same time as the timing belt?

fingers crossed...

[Jedidiahwiebe]

Yup, it took out the timing belt along with it. At least made it skip some. The timing marks no longer line up

I did replace both belts. I last had them off 20 or so thousand km ago when I took it off for a warped head, which I got decked and then put back on myself. This is the shitty thing about doing it yourself. Learning. It's often very painful. The balancer belt in addition to being torn was FULL of cracks and was glossy and smooth. Weird.. I guess the tension was off.

So I have a spare (old) balancer belt. I kind of wanna put it back on, put everything back together and see if it runs. Is it best if I first pull the valve covers off and see if they all move up and down?

[Jedidiahwiebe]

Seems to be a broken rocker arm and a piece chipped off one of the pillow blocks that holds the rocker arm shaft in place. Otherwise the rest of the valves open and close well upon my visual inspection. Be a bit hard to check that valve though...

Both items are easily replaceable, And I'm pretty into seeing how long i can make this engine run. What d'yall say about that?

[thedjjack]

a leak down test on each cylinder at top dead centre with valves closed would let you know the valves are sealing in the seats.... if it passes that I would fix the rockers and put it back together.

did you replace the tensioner? maybe the bearing went and broke the belt. It is fine to run it without the balance belt for testing (some have gone 1000s km without) biggest worry seams to be some loss of oil from balance shaft turning a splasher or something but seems not to be a big deal.

you could line up the marks and see how it runs?? then replace the belts and tensioners if it seems ok?

good luck

[yojimbo]

Rocker arms are sacrificial, v8rick on the uk site who is a mechanic has done a lot of these repairs and says he's never seen a problem. Tensioners should be changed with belts, as mentioned, and I think they need to be retensioned every once in a while, since the spring tensioner is locked down so doesnt take up any stretch.

[Jedidiahwiebe]

Sounds great guys! I will definitely try and do that before I give up on this van! I'm pretty keen to keep it running. I wanted it to be a million mile engine before I was through with it!

As for why the belt broke. I'm at a loss. I would really like some ideas on that one. The tensioners were replaced with the belts 40 thousand km ago. The little guy still spins fine and has no slop. There is a little oil/greasyness in the timing belt compartment but did not appear to have been any on either belt. However the torn nfg balancer belt was cracked to $%*t! It looks a hundred years old! I would really like to know what caused it's failure before putting it back together! The only thing that I could find that was a little bit odd in the balancer belt system is that the left harmonic balancer gear has a teeny tiny bit of slop in it. I guess I should try and tighten that before I get too carried away. But that shouldn't have caused a problem should it have?

I guess the next thing is to do a leakdown test. Then order a new rocker arm and pillow block? Since the pillowblock nearest to the broken rocker arm has a chunk ripped out where the rocker arm shaft is bolted down is it possible that I need to replace the rocker arm shaft too?

Thanks so much guys for your input!

[Jedidiahwiebe]

It's really good news to hear that rocker arms are sacrificial though. I was hoping that was the case. Good engineers always design the weakest link to be easily replaceable right? Sacrificial rocker arm. I like that idea.

[Big-Bird]

Sounds great guys! I will definitely try and do that before I give up on this van! I'm pretty keen to keep it running. I wanted it to be a million mile engine before I was through with it!

As for why the belt broke. I'm at a loss. I would really like some ideas on that one. The tensioners were replaced with the belts 40 thousand km ago. The little guy still spins fine and has no slop. There is a little oil/greasyness in the timing belt compartment but did not appear to have been any on either belt. However the torn nfg balancer belt was cracked to $%*t! It looks a hundred years old! I would really like to know what caused it's failure before putting it back together! The only thing that I could find that was a little bit odd in the balancer belt system is that the left harmonic balancer gear has a teeny tiny bit of slop in it. I guess I should try and tighten that before I get too carried away. But that shouldn't have caused a problem should it have?

I guess the next thing is to do a leakdown test. Then order a new rocker arm and pillow block? Since the pillowblock nearest to the broken rocker arm has a chunk ripped out where the rocker arm shaft is bolted down is it possible that I need to replace the rocker arm shaft too?

Thanks so much guys for your input!

ENGINE MANUAL LINK:
http://www.delica.ca/manuals/L-300%20Ma ... Manual.pdf
You say there was oily residue in the timing cover? According to the engine manual (Read pg 21 of the PDF file) for the 4D56 water and oils/solvent residues greatly impact the life expectancy of the 2 belts. You should check your seals and make sure there is no grease/oils that were weeping out. The belt being cracked is most likely a reaction to heat buildup which can happen when the tensioner pulley slips on the greasy belt and then grabs again....doing that several times under any acceleration and you have premature belt failure/wear.


And pg 22 tells how to check belts for condition....do you know how old the 'new' belt was? Rubber doesn't stay elastic forever and 'shelf aged' belts can harden up in short order when they heat up through normal use. Check the smooth belt surface and see if you can mark the rubber with a fingernail....if no mark is present then the belt heated up and failed....but that points back to the oily stuff you mentioned.

[Jedidiahwiebe]

Thanks again so much everybody for the responses! That's a great point about the leaky front end. I was reading the manual pdf and I just feel like it can be so vauge sometimes ya know? Like how it says to make sure there is no oil or grease on 'any part'... I thought they meant on any part of the belt! I did not realize that the whole front end of the block should be clean and dry! I just assumed that some minor seepage would exude from the seals! (all of which were replaced at the same time as the belts/tensioners/water pump by myself btw.

After re-installing the belts with correct timing I just tried to do a compression test (as acquiring a leak down tester did not seem feasable) I got some kind of compression on cyl 1,3,4 (no idea how much since it was a rubber tipped compression tester. No matter how hard i pushed down some air still blew out on all three! But cyl 2 (the one with the broken rocker arm registers NO compression whatsoever. I guess there is some because if i turn it over slowly with my thumb on top it still pushes up a wee bit on the compression stroke and sucks on the downstroke.

However to my great surprise.. since I was running veggie oil when it died and i had no time to purge it fired right up while i was trying to do the compression test. This was especially surprising since it normally doesn't fire up on veggie, let alone with the glow plugs disconnected. It ran very poorly for a few seconds and then I shut it off.

Sooo I feel like that's a good sign. The compression must still be fairly good in the other three cylinders if it wants to run even with one glow plug pulled out. and the rocker arm fried on that cyl.

Anything else I need to do before ripping off the head for inspection?

[Big-Bird]

You ran the engine with a damaged rocker? Risky.....even by accident.

There are brass fittings that will allow you to adapt the glow plug thread to something the compression tester can fit....like NPT threads and even some standard sparkplug threads. Princess Auto, Acklands Grainger supply and even hydraulic supply shops might have something.

Partsource has a decent array of free rental tools...do you have one near you as they might have a leak down test kit.

A compression tester will tell you quite a lot about engine health.....Diesels are tricky when doing compression tests, you have to disable the fuel system to prevent accidental starts....like the event that happened to you. The factory fuel system on the 2.8L in the L400 has a primary fuse for the fuel shut off solenoid....not sure about the L300.

Also I can't recall if the 2.5 is an interference engine or not.....that means if the piston rides up when a valve is open due to a broken belt a valve will get bent and then won't close properly. If your rocker is bent even slightly it could also prevent complete valve closure and you will get a low/zero compression result.

[thedjjack]

For those who do not know what a leak down test is....

You put the cylinder at the top dead centre with valves closed (top of the compression stroke) then you add compressed air to the cylinder (with adapter through spark plug or glow plug hole) to see how long it takes to leak out... You can add oil to see if the rings are bad, and you listen at manifolds and crankcase to determine where you leaks are.... testers are reasonable priced and just need an air source....

handy if a valve is bent and not closing over a compression test as you know if where the problem is more likely....

[Jedidiahwiebe]

You ran the engine with a damaged rocker? Risky.....even by accident.

There are brass fittings that will allow you to adapt the glow plug thread to something the compression tester can fit....like NPT threads and even some standard sparkplug threads. Princess Auto, Acklands Grainger supply and even hydraulic supply shops might have something.

Partsource has a decent array of free rental tools...do you have one near you as they might have a leak down test kit.

A compression tester will tell you quite a lot about engine health.....Diesels are tricky when doing compression tests, you have to disable the fuel system to prevent accidental starts....like the event that happened to you. The factory fuel system on the 2.8L in the L400 has a primary fuse for the fuel shut off solenoid....not sure about the L300.

Also I can't recall if the 2.5 is an interference engine or not.....that means if the piston rides up when a valve is open due to a broken belt a valve will get bent and then won't close properly. If your rocker is bent even slightly it could also prevent complete valve closure and you will get a low/zero compression result.

No! I actually ran the engine with one rocker missing. Also If the rocker is bent wouldn't it be more likely that the valves would not open properly than that the valve wouldn't be closing? I'm not sure what kind of force could bend a rocker in the direction you speak of? I guess I could check the valve clearances to see if other rockers are preventing it from closing.

Yes the 2.5 is an interference engine. Hence the broken rocker arm I assume.

I do not live near a partsource, princess auto or Aklands Grainger.

[Jedidiahwiebe]

For those who do not know what a leak down test is....

You put the cylinder at the top dead centre with valves closed (top of the compression stroke) then you add compressed air to the cylinder (with adapter through spark plug or glow plug hole) to see how long it takes to leak out... You can add oil to see if the rings are bad, and you listen at manifolds and crankcase to determine where you leaks are.... testers are reasonable priced and just need an air source....

handy if a valve is bent and not closing over a compression test as you know if where the problem is more likely....

Yep, I looked it up on youtube! What I'm wondering though.. is... given my situation is it really necessary for me to go out and buy a leakdown tester? Is there any explanation for my symptoms (slipped timing belt, broken rocker, leaky cylinder) other than that a rod is bent?

On the other hand maybe what I should do is just go out and get a leakdown tester so that I can confirm that the other cylinders are okay before I take the head off and hand it to the headshop to get the valves fixed?

I have one other question for you guys. Everybody reading this thread. Why is it possible (is it even possible?) that I just smashed one valve? If the timing is off for one wouldn't it be off for all of them? The only explanation that I can think of is that the valve smashing occurred while the timing belt was slipping. Then after that it might have landed in a position which did not cause interference?