Diesel motors fuelling off there bypass fumes when they get worn.
Submitted: Saturday, Mar 14, 2009 at 20:45
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Member - Axle
Anyone had that happen?, I had a mazda ute with a 22rb motor that was worst for wear, pulled up at a intersection one day and noticed it was idling quiet fast, next minute it was doing about 40,000 revs and i had my foot no were near the go pedal!!
Turned the key off nothing happened.
In panic mode straight away as this thing was gunna go into orbit, so i tossed a laser level out the window onto the foot path, grabbed a few other things and started to bolt..lol, Something told me "stop", and when i turned around the black smoke had just about blocked out the sun. Talk about REVS!!, When the brain started to work i jumped back in, thru it in fifth cog and dropped the clutch. stopped it but Needless to say that was the beginning of the end for that gearbox..lol. One of the highlights of owning a worn out vehicle.
Cheers Axle.
Reply By: Member - 120scruiser (NSW) - Saturday, Mar 14, 2009 at 20:57
Saturday, Mar 14, 2009 at 20:57
Yep. They rev until they blow. Scary thing.
AnswerID:
354025
Reply By: Member - Paul W- Esq (VIC) - Saturday, Mar 14, 2009 at 21:49
Saturday, Mar 14, 2009 at 21:49
Hahahaha sounded like an adventure, i had a 22R in a ezyloader LWB, it blew a head gasket at 486k, i thought as i had to pull the head off anyway i would chuck a set of rings and bearings in it as it used 5 to 8 ltrs of oil per 1000k around town, more with alot of freeway work, except when pulled down the lip at the top of the
bore was about 1/8th of an inch!!! so just threw it all back together, it went bang about 10 seconds after the first start.
broke the timing belt,stuck a new one on it and she was good to go again, and time to get rid of it which was done promptly. smoked like a bitch but never ran on.
AnswerID:
354037
Follow Up By: Member - Axle - Saturday, Mar 14, 2009 at 22:04
Saturday, Mar 14, 2009 at 22:04
Was yours a overhead cam model?, If so how did you get those sort of ks before head trouble. Could never seal mine up..lol
Cheers Axle.
FollowupID:
622194
Follow Up By: Member - Paul W- Esq (VIC) - Saturday, Mar 14, 2009 at 22:13
Saturday, Mar 14, 2009 at 22:13
Dunno, just regular servicing and always fresh coolant, had no A/C so that helped keep engine temps down. that was the first major blowout it ever had.and yes it was OHC.
FollowupID:
622196
Follow Up By: austastar - Saturday, Mar 14, 2009 at 22:17
Saturday, Mar 14, 2009 at 22:17
I believe our local electricity commission (HEC) had a big generator set do similar back in the early 1970s.
They cut the fuel, but had to clear the area when it started to run on its own lubricating oil.
I guess they couldn't drop it into a higher gear and let out the clutch either.
I was told it was very exciting.
cheers
FollowupID:
622198
Follow Up By: fisho64 - Sunday, Mar 15, 2009 at 02:21
Sunday, Mar 15, 2009 at 02:21
that would likely be a GM
FollowupID:
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Reply By: Malleerv - Saturday, Mar 14, 2009 at 23:42
Saturday, Mar 14, 2009 at 23:42
Yep, had an old hilux that if you pushed it along for a bit it would all the sudden take off in a cloud of smoke, just a bit of brake pedal to slow it down and it would stop till next time.
Matt
AnswerID:
354048
Reply By: Richard Kovac - Sunday, Mar 15, 2009 at 03:23
Sunday, Mar 15, 2009 at 03:23
Hi Axle
Me thing if blow by was so bad how it it have the compression to ignite the by passing fumes,, think about it for a couple of seconds??
This is only a me think statement but only Fax's will back it uo ... LOL
AnswerID:
354054
Follow Up By: Malleerv - Sunday, Mar 15, 2009 at 12:02
Sunday, Mar 15, 2009 at 12:02
Its not the fumes but sump oil held up in the rocker cover by excessive blow by, then the oil is sucked into the intake via the engine breather pipe. This is my understanding.
FollowupID:
622255
Reply By: obee1212 - Sunday, Mar 15, 2009 at 09:48
Sunday, Mar 15, 2009 at 09:48
I read an account of a marine engine taking off on the sump oil that was blowing into the cylinders (bypassing the rings?) Anyway the teller of the tale said the air intake was a straight pipe and put the cheek of his bum up against it. The engine stopped in its tracks but I dont remember what he said about the condition of his backside. He would have had something to say if he got the orifice over the pipe I bet.
owen
AnswerID:
354079
Reply By: Oskar - Sunday, Mar 15, 2009 at 10:45
Sunday, Mar 15, 2009 at 10:45
Saw an old diesel Hilux that did that. They reckoned it was the worn intake valve guides/seals that caused it. Sucked the oil straight in and just kept on revving.
AnswerID:
354086
Reply By: Twinkles - Sunday, Mar 15, 2009 at 13:16
Sunday, Mar 15, 2009 at 13:16
Had a 2.2lt Hilux that used to take off in a cloud of smoke. Only the brakes would stop it. Looked like a James Bond car and used to accelerate. Had the motor done up at 120,000km, by 180,000km was doing it again. Took the rebreather hose from rocker cover to inlet manifold off. Blocked manifold hole and hung tube down side of motor to a catch bottle. Never did it again.
A suction happens that drags the fumes from the sump oil in top of motor into manifold and it feeds on sump oil. The oil is supposed to hit a baffle and drip back down. Would happen after motor well warmed up.
AnswerID:
354102
Reply By: Louie the fly (SA) - Sunday, Mar 15, 2009 at 15:05
Sunday, Mar 15, 2009 at 15:05
We had a Ford Courier diesel with about 240K on it (Mazda B2200) that did that. I was driving home from work on the South Eastern Freeway late one night when all of a sudden it started revving it's what's names off. Must have been doing 8000rpm I reckon. There was smoke billowing out from everywhere. I pulled over and tried to turn it off but it just ran until it stopped. I managed to get it started again and drive it home, about 15 k's. Next day I had a local diesel guy look at it. Motor was completely stuffed so we sold the ute to them. They recond the engine and used it as their work truck. I think it was due to lack of proper servicing.
Louie
AnswerID:
354112
Follow Up By: Member - Axle - Sunday, Mar 15, 2009 at 19:49
Sunday, Mar 15, 2009 at 19:49
Hahahaha, not a nice feeling when you turn the key off, and the revs keep building!!.
Cheers Axle.
FollowupID:
622333
Follow Up By: Louie the fly (SA) - Sunday, Mar 15, 2009 at 20:33
Sunday, Mar 15, 2009 at 20:33
After it had all settled down I realised it was pretty funny. After I turned it off I tried to stall the engine by leaving it in gear and putting the brakes on. It just overrode the brakes.
Years ago I worked on an agricultural research centre. One of the guys tried to start a diesel tractor with a petrol soaked rag (per my instructions). I said hold the rag over the air intake and start it. Trouble was he removed the whole air filter, cranked it and the rag got sucked into the air intake tube. Same deal, it was revving it's balls off for about 30 seconds. Scared the hell out of him. An 80 hp aircooled Deutz sounds really cool when its spinning at 5 grand.
Louie
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