Engine Jamming!

[SIM-12]

Hi Everyone,
I've owned My 1994 KZN130 Surf for just over 3 years now, & When I've had problems I've found all the information needed on this brilliant Forum. However, now I've got some problems & cannot find the answers! Could anyone Advise please?
Had this problem for around 2 months. when I turn the key to start, the starter engages but just jams & doesn't turn the engine over. I read that a common fault was the contacts wearing out, but that symptom was clicking rather than the jamming that I had. But I thought I'd fit a new kit anyway as that might cure it. It didn't. (Worth a try though) The engine was only jamming about once every so often anyway, maybe once or twice a week. It got to the point where I broke down miles from Home. Rang RAC, He banged on the starter motor with a metal bar. It started! He said it needs a new starter motor. So I fitted a new one. I still have the problem! It took a turn for the worse last week, as I went to start it up & it jammed, followed by a really loud clattering noise!! I tried to turn the engine by hand with a socket & breaker bar on the front pulley. It wouldn't turn! I thought the engine was seized! I rang the RAC. Meanwhile I tried to turn the engine the opposite way. It turned! I turned it the right way again & it turned! I tried to start engine again &...It started! (I cancelled RAC Call out). It's been nearly a week since then & everything has been fine! BTW, once the engine is running everything is fine like normal. The auto gearbox seems ok too.
Has Anyone else had this problem? Does Anyone have any ideas of what it could be? Any help or advice would be greatly appreciated!
Many Thanks..Simon

[andyverran]

What state are the teeth on the ring gear like?

[surfenstein]

When you replaced the starter motor did you notice any metal fillings on the bendix of the old starter,

[SIM-12]

Thanks for your replies Guys. The teeth on the Ring Gear are fine, just normal. The Bendix on the Old Starter have no Filings on them at all.

[charvell]

have you checked the earth and electrical connetions

[SIM-12]

Thanks Charvell, I've checked All of the battery connections, The main cables & the Earth connections too. I've cleaned up Everything I can get to. I've been using the Surf Every day for about 9 days now & that problem hasn't returned yet!

[nismo33]

You running veg oil?

[SIM-12]

I was running it on veg oil for about a year, up until September 2014. Since then just Diesel.

[nismo33]

Mine jammed couple of times after i started using veg oil. Nothing to do with the starter..........just jammed cos it didnt fire up 1st time. Could be your glow plugs

[Diezel Weazel]

Been running WVO/SVO for over 10 years+ & never had this problem ....
Has ya Truck ever got HOT or over heated ?

13+ Years of Surfs ..... n Faultless to a "T" is my Yota !!

[SIM-12]

When I was using veg oil I never had any problems with the Engine jamming. I haven't checked the glow plugs though. That's a good idea. Thank You Nismo.

My Truck hasn't got hot or been overheating, however The radiator is around 6 months old & ever since fitting it & refilling with Anti-freeze etc, I've never got rid of an airlock as coolant keeps filling up the expansion tank! ( I've done all the tricks to prevent the air locks, but it's still the same!) I'm glad to hear that Your truck runs well on WVO/SVO too. Thanks for your help Diezel Weazel.

BTW, My Engine Jamming fault still hasn't returned yet! It's been about 19 days since that breakdown!

[davec170]

Sounds just like a head with a fine crack. Coolant seeps into one combustion chamber when the engine is shut down and the cooling system is pressurised. If that cylinder is on the compression stroke at next start up it can hydrolock.
Look for a small puff of steam from the exhaust on the first start of the day. Also keep a close eye on your coolant level.

[SIM-12]

Thank You very much for that Dave. Apologies for late response! I think that could be exactly what you've said! The engine locks up from time to time, & it frees off when I turn it both ways with a socket on the front pulley! I'm topping up the rad nearly every day. I checked the engine oil level the other day & that has risen. I drained some of the excess oil out & when I first undid the sump plug a small amount of water drained out first. Also the water is bubbling in the expansion bottle. I guess this all means a New Cylinder head?

[davec170]

I'm afraid it probably is. :-(
You can confirm it, if you wish. Next time it locks up don't free it up by " backing up" the engine. Remove the glow plugs, get someone to crank it over on the starter whilst you watch under the bonnet. If it's what I suspect you will see a spurt of water shoot out of one (or more) of the glow plug holes. Number 3 cylinder would be my bet ;-)

[SIM-12]

I think you've hit the nail on the head Dave. I will do that test anyway & I'll let you know which cylinder(s) spurted out water. Many Thanks! Simon