Knock/tick/tap/manifold leak...??

[fletcher969]

Ok, I'll probably overkill on the info, but here goes, and thanks in advance for anyone who reads long enough through my diatribe and responds!

1998, 2WD, 209K miles

3 weeks ago: My radiator blew a 'vapor' leak right at the hot water input. I caught it just as the temperature gauge started rising, and it never hit the red before I coasted to a stop on the side of the road. I ultimately topped it off, released the main cap just enough to prevent full pressure build-up, and drove it home. And I'll mention it just in case it's relevant, but the radiator isn't yet fixed/replaced...just too busy with work. Instead I've kept the system topped off daily, and it's run fine from a temperature (gauge) standpoint. I plan to repair or replace it later this week actually.

2 weeks ago: My starter gave out, so I replaced that, and started home. About 6 miles of highway later I observed an almost indiscernible 'fog' behind me, scanned my gauges and noticed my oil pressure gauge was at zero! Temperature gauge was holding steady in the center, but I assumed a complete loss of oil; however, before I could let off the gas and coast to a stop, my engine starting to tick noticeably along with a loss of power. I coasted for about half a mile to a country store parking lot. Temperature gauge never changed. Long story short, positive cable on starter contacted the filter, and burned a hole through it. I rectified that situation, refilled with oil (GF purchased synthetic which I've NEVER before used in this vehicle), and started it up. It rattled/ticked for about 2 seconds, then settled down, ran as smoothly as before, oil pressure was dead center as before, and I didn't hear anything unusual for roughly a week.

1 week ago: I started hearing a light ticking/tapping noise when the engine was under a load. Definitely didn't sound like a rod knock, so again, too busy, decided to just monitor it since I've not observed any discernible performance decline or change in oil pressure. Figured it was likely a lifter issue, so I tossed half a quart of Marvel Mystery Oil in it I had on hand to see if that might free it up. Might be worth noting that my oil level had dropped about half a court with no external indications of a leak. Anyway, no real change in the situation until 2 days ago when the ticking noise became more like a soft knock...enough to concern me. In park or at idle, almost indiscernible, not much more to hear when revved up in park. Same sometimes when it's running in gear on level ground. Under load, noticeable, particularly when going uphill. I put a stethoscope on it, and the sound appears to come from the front cylinder on the driver's side (#4?), but I only ever get an indication when the steth is on the exhaust manifold. Nothing at all when it's on the valve cover or oil pan, and slightly less indication when the steth is on the exhaust manifold on the cylinder next to the aforementioned cylinder. Unplugging the wire from the front cylinder drastically reduces the noise at idle (can't say with certainty it fully eliminated it...at this point I'm hearing ticking/tapping in my sleep). I noticed the 'silver' exhaust manifold gasket material was falling apart on the driver's side (exhaust is the original). At that point I was thinking this is either a rod bearing failing or an exhaust manifold leak.

Yesterday: I decided to change the oil so I could look for evidence of bearing wear and/or failure. The oil was VERY cloudy (after approximately 500 miles...the Marvel Mystery Oil?). Like super fine dust, and with an LED light on it I could detect a few...very few brass-colored 'dust' particles, but the oil was void of any 'pieces of bearing material, not sure, maybe those would be in the pan. Decided to just refill it with non-synthetic 10W-30 oil (old filter in place). That actually did wonders. While the sound isn't completely eliminated, it is far quieter than it was before. More like a lifter tap than any degree of knock, and now it doesn't show up at all until after the engine warms up whereas before it was evident whether the engine was cold or warm. Still mostly noticeable when under a heavier load (after warming up), but a couple of times it didn't make any discernible noise while going uphill. I hate inconsistency! The oil pressure is steady. No change whatsoever.

Any ideas? I figure I'll probably end up dropping the pan and inspect my bearings (and replace them regardless given it was run without oil for a mile or two), but anything I might do to really zero in on a cause until I drop the pan later this week?

 

[Angie]

I am not in the know of a 3L. however, from what you have stated, I really wouldn't go through the trouble of tearing apart a running engine for no reason. Unless you are a confident mechanic with a proper hoist, taking off an oil pan with the engine still in a vehicle is a job within itself. If you go that route, good luck to you. to tear apart an engine just to "inspect" the bearings is a feat within itself and will open up the greater possibility of getting serious contaminants inside the engine. Dropping the pan and changing the bearings? I wish you all the luck in the world.

if it was my situation, I would buy a couple spare quarts of oil, and a spare jug of coolant and buy proper mechanical gauges for the engine. monitor what is going on and drive it.

good luck

 

[fletcher969]

I am not in the know of a 3L. however, from what you have stated, I really wouldn't go through the trouble of tearing apart a running engine for no reason. Unless you are a confident mechanic with a proper hoist, taking off an oil pan with the engine still in a vehicle is a job within itself. If you go that route, good luck to you. to tear apart an engine just to "inspect" the bearings is a feat within itself and will open up the greater possibility of getting serious contaminants inside the engine. Dropping the pan and changing the bearings? I wish you all the luck in the world.

if it was my situation, I would buy a couple spare quarts of oil, and a spare jug of coolant and buy proper mechanical gauges for the engine. monitor what is going on and drive it.

good luck

Thanks for the reply.

I've swapped out rod bearings with the engine still in the vehicle (and also with a tractor), but admittedly it has been awhile, and I must have been lucky with the vehicle with which I was working, because the oil pan drop wasn't a project in itself, and I had 'relatively' easy access to the full length of the crankshaft (the tractor was very easy). That's apparently NOT the case with my Ranger. That said, I do have a hoist, but I'm not sure I want a reason to use it just to inspect the bearings. At least not yet, and only because my gut says it's not a rod bearing making this noise. I just thought it would be a much easier proposition than it is to inspect the bearings to possibly avert a worst-case scenario. Given what I know now, I think I'll search for an exhaust manifold leak, and hope that's what this is.

 

[Angie]

hi, I am not saying it can't be done, but is it needed is more my point. sometimes for that type of adventure, isn't it easier to pull a motor? I was talking with a friend who has done a 3L with it in the truck (a oil pan gasket job) said it wasn't bad but a pain. Somehow the oil pick up worked, but he had to lift the engine by taking out the mount nuts, and unhooking the transmission.

Always start with the easy stuff... cheers

 

[fletcher969]

hi, I am not saying it can't be done, but is it needed is more my point. sometimes for that type of adventure, isn't it easier to pull a motor? I was talking with a friend who has done a 3L with it in the truck (a oil pan gasket job) said it wasn't bad but a pain. Somehow the oil pick up worked, but he had to lift the engine by taking out the mount nuts, and unhooking the transmission.

Always start with the easy stuff... cheers

No, your point wasn't missed, and it was appreciated. I simply thought dropping the pan was far easier than it is, and assuming so, I wanted to address what could be the worst case situation if left unchecked too long (i.e. rod bearing).

That said, I took a different course, and I decided to first eliminate my exhaust's extraneous leak noises to better isolate the sound or conclude that it was an exhaust manifold leak. When one of the leaks I found was in fact an exhaust manifold leak between the mating surfaces at the #4 cylinder I had my hopes up that was the noise I was hearing; however, with the extraneous noise gone, it's clear I have a distinct tap/tick right near the #4 cylinder (front of engine, driver's side) that I'm pretty sure is a metal-to-metal sound (through the steth), and a couple of times I thought I heard a short 'rattle" of sorts. Maybe I was imagining the latter... With a steth it's most clearly audible when I place it on the exhaust manifold coming out of #4. It becomes less and less obvious the more I move away from that spot, but it is faintly detectable on the other side of the engine when I touch the exhaust manifold and block. No noise except a whirring whenever I touch the valve covers or the rear of the exhaust manifolds (farthest away from where #4 is). Can't check the front of the engine given that's where everything is moving. Whatever it is, the #4 cylinder or something VERY close to it is involved. My guess would be a lifter, but I can't hear it through the valve cover, and I can't be sure without a timing light, but it seems to be a full-time tap/tick versus a half-time tap/tick.

Now, I may have a different issue to deal with, and maybe it's related, but I have from time to time smelled fuel whenever I've stopped the engine. Noted, but not a consistent enough of an observation to prioritize. The other day I smelled it again. Looked for fuel in/around the engine, but found nothing. That day I also noted what I thought could be the smell of fuel in my oil when I emptied it (dismissed that at the time for some reason), and again today when I sampled the oil on my dipstick, and my neighbor who happened by today concurred. He also smelled fuel when I shut the engine off. We looked for signs of fuel again, but found nothing. Still, the smell of fuel outside the engine and in my oil makes me think I have a leaking fuel injector. Related? I dunno...