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be damaged by low oil pressure after a timing belt snaps in the time it takes to coast to a stop at 70mph?
i ask because i snapped one yesterday, the first ever and after towing it home and reinstalling a new belt i hear an odd lower end sound very faintly and very sporadically an only for a second and its gone.
it almost sounds like a wrist pin not a rod and surely not a main.
oil light goes out within a second or two upon startup and has not come on at idle or at speed. have not yet put on a mechanical gauge.
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My student driver son was driving at 70+ mph about twenty years ago when the 50,xxx mile timing belt broke. I replaced the timing belt at the Gee Creek Rest Area adjacent to I-5, in 36° F weather. My wife drove the car for about 15 more years, when it was sold. There were no problems from the broken timing belt while we owned the car.
--
john
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thanks john. just removed an oil pressure gauge to satisfy mnyself and found 50psi at warm idle going up at higher rpms.
i am frankly glad i was able to repair it in my driveway as opposed to rest stop. the harmonic balancer was not at all happy being separated from the crank shaft. that took quite a while of coaxing. the rest of the job is connecting the dots.
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You can't really call yourself a "Brick Head" until you've changed at least one Red Block timing belt on the side of the road....or a parking lot.
It's a right of passage.
We're getting old and scarce.
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Dear HillBilly,
Hope you're well. Does changing a drive belt (alternator) in a parts store parking lot count?
I try to keep on schedule with timing belts, rad/heater hoses, etc. and - thanks to maintenance records in spreadsheets - so far have done so.
Yours faithfully,
Spook
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thanks guys!
the 1993 car is mine for many years and apart from regular oil changes and such i tend to forget about certain things so, like the cobblers children my car tends to get shoes last.
what i did notice was the oil light stayed on for 5 seconds after the belt snapped. i placed the car into neutral to prolong my coast to reach a wider safer shoulder on the highway ahead about 1/3 mile.
the pressure has always been in the 40-50psi range but i have not done this in 6 months at least. will have to stick gauge on this week to see whats up.
it seems to run just fine, start first time, idles smooth with decent enough power for a 300,000 mile NA. its not like the car owes me anything.
art, i use the generic oil pressure kit from harbor freight. there are enough adapters to make suitable test situation not too hard to screw in or off.
https://www.harborfreight.com/engine-oil-pressure-test-kit-62621.html
actually i am grateful it broke heading to the grocery store rather than fully loaded with "meltables" in the bags because it took 90 minutes for the tow truck
to arrive. that's a lot of ice cream to eat while you're waiting
oil stuff in the kit art
1/8 in-27 NPT male/female 90° elbow, 1/8 in-27 NPT female x 1/8 in-27 NPT female, 1/8 in-28 BSPT male x 1/8 in-27 NPT female 90° elbow, 1/4 in-18 NPT male x 1/8 in-18 NPT male, 1/4 in-18 NPT male x 1/8 in-27 NPT female, 3/8 in-18 NPT male x 1/8 in-27 NPT female, M8 x 1 male x 1/8 in-27 NPT female straight, M10 x 1 male x 1/8 in-27 NPT female straight, M12 x 1.5 male x 1/8 in-27 NPT female straight,
M14 x 1.5 male x 1/8 in-27 NPT female straight,
1/8 in-27 NPT male to male 2 in. long nipple,
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Hi Ted,
Oh, your own car. My guess was toward one you might have just picked up at an auction.
Thank you so much for the tip on HF having the whole kit. Their prices have always been better than piecing things together, so I've put one on my list. Last time I needed one, I had the idea an old compression gauge would do, thinking M14 but quickly finding out spark plug M14 is 1.25 pitch and the oil sender port is 1.5.
Lucky it was just the sender bad, so screwing in a junkyard spare put off the need to do a measurement. A look inside the old sender made it clear the oil was leaking past its diaphragm. That might even be the reason your light stays on so long after starting the car. Really, if you could say "one thousand one" before that light went out after releasing the key, something isn't right. And once the belt snapped, the light should have stayed on until you turned the key completely off, which I take it must have been more than 5 seconds.
Is the noise you heard still there?
--
Art Benstein near Baltimore
Brickboard members are the most likeable, smartest, and best-looking people on the internet. [Citation needed]
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Dear trichard,
Hope you're well. Once the timing belt snaps, the engine stops, because the RPM sensor's signal is lost. That causes the Engine Control Module to turn-off the fuel pump(s).
At 70 mph, the engine was turning at about 3,000 revs. It could not have taken more than a handful of seconds for the crankshaft to stop turning. During those few seconds, no combustion occurred because the fuel pump had shut-down.
If ambient temperatures were, say, 50 degrees, air-cooling - as the car drifted to a stop - would have drawn heat from the block, prolonging the lubricity of the oil on cylinder walls and bearing surfaces.
In short, I'd guess residual oil prevented damage. I presume: (a) oil level was correct; (b) oil was within normal change interval (say, 7K miles).
This conclusion is bolstered by brief time that oil light is on, which is within normal limits. I suspect a gauge will show normal pressure, i.e., about 43-44 pounds/square inch. This is based on data in the Volvo pocket data booklet - Cars (700,850,900) 1991-1996, p. 26. At 3,000 rpm, oil pressure is given as 0.3MPa = 43.5 pounds/square inch.
Whether there was any damage to wrist pins might depend on the model year. Post-1993 B230 engines' oil squirters keep that area well-lubed. Thus, on a 1993 or later engine, I'd presume enough oil remained to prevent damage. On a 1992 or earlier engine, I'm less confident.
Hope this helps.
Yours faithfully,
Spook
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Hi Ted,
It sounds farfetched to me, but I see your point if you're sure it is lower-end noise. I'm guessing you don't really have a good handle on the maintenance history of this unspecified 4-cyl volvo, so the T-belt snap could have been the culmination of poor oil distribution.
When you replaced the belt, did you find any clue to poor oiling at the camshaft?
Oil light takes a second or two to go out? Seriously? Or is this a guess?
Speaking of mechanical gauging, how have you solved the problem of getting an M14-1.5 connection for your pressure gauge? I haven't built one yet, and my thinking is a gauge adapter (common part sold for conversion to gauge senders) would need some good threadlocker if used with a 1/8" NPT hose end.
--
Art Benstein near Baltimore
Eat, drink, and be thoughtful.
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