'84 240Ti Part III

Thank you to all who helped diagnose the wiring harness having
degraded its insulation - as the cause for my gauges going wild.

I had the harness removed and each wire re-wrapped; GREAT IMPROVEMENT.

I noticed on the way home (once again from that shop) that now the Oil
guauge needle goes all the way over to the right and stays there until
I switch off the engine.

Would that be related to that same harness?

Maybe they rewrapped a wire incorrectly?

I'll have to take it back, I guess, if some other cause doesn't arise.

The 5 bar oil gauge was working fine untill the wiring harness fiasco.

Could yet another problem witth the wiring harness be the culprit?

Thank you.

Allan Ballard
Atlanta, GA

1989 240 195K daily driver
1984 240Ti 215K project car being restored ror a long drive around
the nation in 2 to 3 years.

 

That means that the green wire going to the oil pressure sender is off.
The oil pressure sender is just behind the alternator, just below the
exhaust manifold. You may need to remove the alternator to work on it.
Start with a cold engine!

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Ok, I'll give it a go.

I took it back to the shop; they checked the sender and said the gauge
was bad.

I tried two others, both hid the needle to the far right.

If the alternator has to come off...does the belt tighten just to
"firm" as gauged by hand, or does it need some special setting?

Thank you.


Allan Ballard
84 240Ti - getting stronger! day by day.

 

They should be as loose as possible (to save bearings) without
slipping. So check how they are now, if they're reasonably firm (and
not slipping), just put them back the same way. If they're hard as a
rock, put them back a little looser. If the belts slip, tighten them a
little.

P.S. I just fixed this problem on my brother's 83 240 Turbo. The
terminal on the end of the green wire had cracked and wouldn't stay on,
so I had to remove the alternator to get enough room to attach a new
terminal. With a light, you can actually see the sender between the
alternator and the heat shield below the exhaust manifold if you
position your head just right.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

You don't have to remove the alternator. Take the plastic pan off underneath
the engine and you can get to it from there. The insullation falls of there
and the wire touches the alternator. Usually a simple fix.

 

I'll take a closer look. The car lost the plastic pan long ago, so
I pulled the passenger front wheel onto a flat piece of granite
I use.

Underneath all I could see was a blue wire ascending to whereabouts
unknown.

Maybe it's a replacement from the green, or else maybe there are two
wires, and the green one is missing.

The shop guy checked the sending unit, said it's ok.

They think the gauge is dead.

However tonight I swapped out two such oil pressure gauges and both
do the same thing.

The needle at once goes to the extreme far right, and stays there.
Once the engine is off, it goes back to the far left.

Maybe there is a wire shorting out, as you say, or possibly one
missing, but it sure sounds local to that wire(s).

 

Under the crankshaft pulley is the end of the engine wiring harness.
Follow that toward the alternator. Inside the harness will be a large
red wire (alt power), a small red wire (amp light), a black wire (oil
light) and a green wire (oil press gauge). Keep in mind that the large
red wire is essentially connected directly to the battery, unfused.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Thanks.

I took the car back to the shop that repaired the harness, along with
two other Oil Pressure gauges behaving the same as the original one.

They said they had replaced the wire to the sender; maybe that's why
it is blue not green, and had tested the sender to be good.

They believe the problem must be between the firewall and the gauge.

I supplied them with all the wiring from a good gauge to the harness.

Might know by tomorrow.

Allan

89 240
84 240Ti

 

TURNED OUT TO BE THE SENDING UNIT, OR SO THEY SAID.