240 Starts then dies, screaming noise from engine

[steve roche]

Perhaps 'screaming' is not the right word. How to describe an engine noise? I've been fixing up old cars for twenty years and I still can't accurately convey a noise, but this one has me worried.

85 Volvo 240, got all the vacuum leaks squared away and turned the distributor cap to make the car start and run smoothly again (after the Smog Test Guys messed it all up)... it was trouble-free for 4 weeks, then this morning after a half-hour ride to work, we started it a second time, to move the car up a bit, and it started up with an angry noise... not a cylinder noise or a rattle but something that reminded me of when there is a hole in the intake manifold or a large vacuum hose has come off, or a rear-end has lost all it's gear oil and you are driving fast. Or, the sound Godzilla would make in a sound studio if the script called for him to "make a car engine sound."

That, and it dies immediately. But it re-starts right up, but dies immediately. I can keep it going by gunning the gas, but that isn't going to help things.

I can't find any more vacuum leaks, cracked manifolds, belts rubbing on anything; but the noise is coming off the engine itself. Even if I get the stalling issue fixed, that noise makes me not want to drive it, and I have driven a lot of half-restored cars in my time.

I will try to pinpoint the source, maybe a frozen AC compressor or power steering belt, but it sure is a little louder than that, and not back where the fuel pumps are.... it doesn't seem like an exhaust manifold noise or an exhaust donut leak. Perhaps like an engine that has no oil. The starter occasionally 'misses' the flywheel, but that grinding sound is temporary and it is not this particular sound. It has been left parked across town so I have only had a few minutes to look it over.

This does not feel like a repair that I will be able to diagnose. Oil is good, tranny fluid may be ok but there is a leak. It was quiet enough driving that morning. Did it blow a freeze plug? I've never done that. There is less water in it than when it was filled a day before. But no puddles. Last week the brake booster vacuum regulator thingie blew itself off, making a whistling noise, not this loud however. It's fixed. It's idle is brief (before it dies) but smooth. But that noise... yikes. The water pump is only a few months old.

Also, did I goof by changing the timing so it would start up easily? (I turned the dist. cap counter-clockwise a few degrees). Seemed like a good idea at the time.

Is there a Childrens' Treasury of Weird Volvo Sounds that I could reference?

Meanwhile, I'll go after the fuel issues, if that is why it is stalling.

It's a mystery--
steve

[steve roche]

I found the problem, I think. It wasn't the starter pinion, that would be too loud (and it does get jammed
every tenth start).

It was a large 3/4 inch diameter vacuum hose going from the airbox, under the intake manifold, and up over it.
It connects right in the top center! I am sure I looked over all the vacuum hoses but I only noticed it after pulling out
the AMM plug and determining that the AMM is not at fault. There is a giant sucking noise, which explains the
screeching noise over the engine noise, and the instant engine-death. The way high winds can howl.
And, usually I find the hard stuff.. if it is right there in the middle, I never notice it.

One thing I cannot explain-- when I pulled the AMM (or MAF) plug to see if it would still start and run,
it started all right, and the engine raced VERY high. I had not heard that this would happen if I unplugged the AMM.
Supposedly if it's defective, you unplug it--- and the car starts and runs poorly, but you can get home.
I tried it five times, and the engine raced high (probably over 4000 rpm) so I shut it down quickly.

I hope my AMM plug does not come off in regular driving, or I will have a Death Machine...

So it's all back to normal; the next order of business is to hose clamp ALL vacuum lines and secure all electric
connectors, as this engine just likes to roll back and forth, disconnecting itself from everything.
I can move the engine this way and that, with my right hand... no, I do not have the funds for new motor mounts.
I need to strap it down like a crazy person before it hurts itself!

So, problem fixed, loud air leak and engine dying immediately, caused by very large intake manifold vacuum
hose popping off (slightly). Not immediately found, due to the mass of black grimy hoses and fuel injection junk
which obscured it.

(also the growing terror that this would be an expensive Volvo troubleshooting and
repair operation... unhinged me, and I could not calm down enough to be methodical about it)

Since iPhones now talk to you, would it be asking too much of Volvo to have the car talk to you,
telling us... "please check the vacuum leak in hose number seven" or " you left your gas cap off"..
or even.. "I have 225,000 miles on me, this is as good as it gets.."

sr