i think it's dead...

[19bonestock88]

i was driving my ranger last night taking out some garbage, turned around, got on it a little (3500 or maybe 4000 RPM in 1st), and i heard a loud horrible metallic noise(bang or knock or something internal), the truck stumbled really hard, and then had no power and made a horrible metallic knocking sound(kinda like a metallic version of popcorn popping) under throttle. it sounded fine as long as i was coasting in gear though...

i limped it a mile or so to my grandmother's house(closer than my house), shut it off, and looked around the block for a hole, assuming that i had thrown a rod. maybe it was bad lighting, but i didn't see a hole, and it restarted, but with the same sound as before when i would rev the engine, and occasionally at idle, accompanied with a stumble.

i called someone in the neighborhood who is a better mechanic than me, and he said i had blown the engine(like i had been fearing) but the fact that it had restarted multiple times has me second guessing what really happened...

any insight?

 

[alwaysFlOoReD]

A rod or main bearing gone will allow restarts. I'm currently swapping motors in my neon for that reason.

 

[RonD]

If the engine restarts I doubt it's anything in the bottom end of the engine, usually that locks an engine up.

Could be a valve broke, I would pull the valve cover and see what things look like.

I wouldn't run the engine any more

I would drain the oil and have a look at what comes out

 

[19bonestock88]

If the engine restarts I doubt it's anything in the bottom end of the engine, usually that locks an engine up.

Could be a valve broke, I would pull the valve cover and see what things look like.

I wouldn't run the engine any more

I would drain the oil and have a look at what comes out

Thats an interesting idea... I plan on going back today and looking the block and oil pan over to find a hole... If it threw a rod, it had to go somewhere, right?

And i didnt plan on running the engine for any length of time other than maybe to drive it o to a rollback...lol

 

[19bonestock88]

Far from dead indeed...

I checked out the truck, found no hole in the block... Oil level was fine... I cranked the engine and it started with normal amounts of fuss, but ran like it did yesterday... Shut it off after about fifteen seconds, and done a compression test on it, got between 140 and 143 psi of compression across the board, with cyl 1 being lowest at 140... Its spitting stuff up through the intake, as evidenced by a cloud of vapor coming out of the carb when cranking or running... The test showed that when no.3 was plugged, the intake had vapor coming out... This would indicate an issue with the intake valve. My mechanic said that it was bent... Guess the head needs to come off, but it will live to run another day...

 

[Mark_88]

Sounds like the noise my 2.0 made when it finally died...but it was the valves making the noise...metalic popcorn is exactly what it sounds like...or a big long zipper amplified...

I ended up swapping the whole engine but I think I could have made it last a bit longer with some Lucas or similar lubricant...

With mine it was -30 and I had to stop twice to fill up the oil...so much pressure and blow-by was chucking the oil out faster than I could put it in...didn't help that had to drive into a 60 Km/hr wind that night but it did make it home and even started the next day...took it for a run and the same symptoms...rattle and no power...like all the valves were open...

Anyway...if your oil is good and you don't see the blow-by pushing it out I'd put in some Lucas (about a half bottle) and run it for a bit...shut it off and then start it again...the noise usually goes away...freed lifters or whatever...

 

[19bonestock88]

Yeah, the oil is still good and there doesnt appear to be any blowby... Nonetheless, i do think it needs more than just some Lucas oil... Probably gonna get new valves...

 

[RonD]

Compression is low across all 4 so timing belt has probably skipped.
I would expect above 165psi.

That would also explain the back flow of air out of the intake

 

[19bonestock88]

I just done the timing belt not 2000 miles ago... The cam timing should be fine... The truck has 171,xxx miles that i know of, which would explain the compression numbers but they seem fine to me... Im only at 9 to 1 for now...

 

[RonD]

Maybe a bolt let go on the Cam gear, 2000 miles after could be a mistake or bad new part in that belt job.

 

[19bonestock88]

It might explain the back flow, but would it explain back flow only on the third cylinder?

 

[RonD]

There is only 1 compression stroke on each cylinder, exhaust valve is open on the other up stroke of the piston, and since #3 has compression I can't see a non-sealed valve causing the backflow, that cylinder would have 0 or very low compression.

The 4 cylinder Fords did have an issue with pinging, and that causes overheating in the cylinder, this can cause the valves to "tulip", the edges cup out.
This cupping prevents the valves from sealing because the stem is now sitting higher so even at 0 cam the valve is partially open.

 

[19bonestock88]

Im confused... If the valve was bent or cupped, or just stuck partially open, it would have no compression on that cylinder, but it has good compression, and is only blowing through the intake on cyl 3... With the plugs out, none of the other cylinders were symptomatic... I would think that if the cam timing were off, it would blow through the intake on all cylinders, right? Would i be looking at a damaged cam follower?

 

[RonD]

Yes, the checks you have done and the symptoms you have observed don't seem to match a specific issue.

The noise is a mechanical issue, and since the last service was the cam/crank timing that would be were I would start, under the valve cover.

 

[19bonestock88]

Found the issue... Cam was slapping the no 3 exhaust valve follower, and wore it to the point that it puked out when i got heavy footed, causing the valve to simply not open, causing the built up pressure to have to evacuate through the intake when that valve opened... Hence the blowing through the intake whilst keeping strong compression on all cylinders... It needs a cam and follower set, and i have just the perfect one picked out...
http://www.summitracing.com/parts/cca-cl70-127-6