Rod bearing noise ?

My 89 240 started making noise while I was driving a few day ago.
Sounded like a ticking sound not knocking, but close. I started to
see some oil smoke from under the hood, I pulled over and the oil was
gushing from the front of the motor.(I had no upper front timing belt
cover on it) Yesterday I found that the intermediate shaft seal was
hanging in front of its hole, only held in place by the gear. I
changed it and the front cam seal and timing belt while I had it
apart. Filled her back up with oil and its still ticking/knocking.
Not extreme, but I suspect its the rod bearings. Looks like these
wont be too hard to replace after dropping the pan. Could this be
anything else (mains ?) and how safe is it to drive it short distances
in town for the next week. It 5 minutes to work each way for me at
35mph. Also what brands of rod bearings should I look at or avoid,
and who has the best online pricing ?
Thanks again for any advice and or suggestions,
Jack in Dallas

 

Did it lose oil pressure? You don't mention anything about the oil light,
did it ever come on? Don't forget to eliminate all the external causes of
the ticking you can think of before you tear into the engine. Dropping the
pan is a bit of a pain, you have to lift the engine up a bit. If I were in
that position I'd look into getting a low mileage motor from a junkyard if
it is something internal, but they're only $140 here. If it lost oil
pressure there could be other damage and if intent on keeping that motor it
might make sense to get a full rebuild.

 

Oil light hasnt worked since I got this car. Ticking sound isnt a
knock yet but it seems to be coming from within the motor. I am
babying it until I can do the rod bearings but if i put a load on it
the noise gets a bit worse. It's just noticeable when driving. I dont
have the money or time at the moment to drop in another block, so it
looks like I am going to have to do a bearing job on it for now and
hope for the best. When I topped it off after the seal job it was
about 2 1/2 quarts low. Lost a lot of oil when the shaft seal blew.
Thanks James,
Jack in Dallas

PS - any recommendation on bearing brands ? Glycol seems to be the
cheapie that the online dealers stock now but Ive never heard of them.

 

That's not cool, that means you very likely did lose oil pressure, can't
help you with the rod bearings, never had to replace them, but it's very
likely you have some head damage too, I'm surprised the camshaft didn't
sieze. The oil light circuit is very simple, I suggest you fix that first,
it's just a pressure switch that grounds a wire to the bulb.

 

I have found that when you have a knock that gets louder with a load, it is
generally the main bearings. Rod bearings get louder on decelleration.

Sorry to be the bearer of bad news. That engine is still worth throwing some
bearins in, though. IMHO

Bernard
1987 240

 

Thanks for the info guys. I ordered a set of rod and main bearings
yesterday. I also got out an oil pressure gauge to put in the dash.

 

What's wrong with the warning light? Does it come on when you turn the key
on before starting? If so then check the wire to the sensor switch, if the
wire isn't crumbled off then check the switch, it's cheap. If the light
never comes on then it's probably simply burned out, the dash indicator
lights are easy to replace. Never hurts to have a guage I suppose, but there
isn't a good place to install more guages on a 700, at least not on the
Turbo models, they came from the factory with every spot filled.

 

New bearings the wrong size will be worse than bearings worn a few
0.001s inch out of spec.

What if your rod journals were ground 0.010 undersize once upon a
time? Talking, looking and wishing do not replace measuring.

It is criticaly important to check the as-installed bearing clearance
by some means. Plasti-gage is one way. < $5