Petrol like Water?

[wally~e28]

My spellling is a little off: should have been durafix. Australian distributor here:
http://www.rc-on-a-budget.com.au/shop/cgi-bin/cp-app.cgi

As i said, worked a treat for fixing holes in cases (timing case "redesigns" from a snapped timing chain on an expensive engine...., broken motorcycle bits, head work etc). I used a hand held torch hooked up to my BBQ bottle (cooked snag in 3.4ms anyone...)
It would be interesting (and fun) to compare breaking a structural join with it, as compared to a tig weld.
TIG is great, if you can organise it and you get a good price from your friendly welder.

I agree with you on maintaining your timing via the flywheel: I use the harmonic mark as a rough guide when I want to "point and shoot" with the light to check, rather than the mirror hassle. The harm balancer also has a bit of error in it, so you see a bit of a smudge for your mark rather than a distinct line.



On this e23, my "money" would be on a dodgy coolant temp sensor. If the wire is broken, or sensor faulty, the jetronic ecu thinks the engine temperature is -30c, and richens it up bigtime. Apparently theres a procedure in the bentley for testing this sensor (of which I dont have a copy).

[kyM bMw]

wally e28.
i think you could be right about the collant sensor..
my needle on the dash board sits at blue (cold) all the time.. and moves up to the 1st line from cold only.. never has it gone that to the 2nd bar or over that. it has only gone over that when my water hose delivering the coolant/water to the engine got ripped and all the water just come out instead of going to the engine at that point the needle went to red/hot straight away because i had no water in the engine.

[ACE-E28]

Originally posted by kyM bMw
wally e28.
i think you could be right about the collant sensor..
my needle on the dash board sits at blue (cold) all the time.. and moves up to the 1st line from cold only.. never has it gone that to the 2nd bar or over that. it has only gone over that when my water hose delivering the coolant/water to the engine got ripped and all the water just come out instead of going to the engine at that point the needle went to red/hot straight away because i had no water in the engine.

That could also be from the Viscous clutch on the Fan assembly (Worn) if it has never been replaced then you should do it..and it might help your Econmy...plus runnig cold all the time is/can be just as bad as running hot for Alloy cylinder heads...if it goes up when very hot..id say it was working..but not necesarly properly.

Check both and replace...Temp switches ar quite cheap...Viscous clutch can be pricy! about $175 brand new

[wally~e28]

Hmmm.

kym. Your gauge has a separate sensor than that used by the ecu. If you unplug your temp guage, your ecu temp sensor should still be functioning fine. Conversly, your temp gauge could read 120 degrees, whilst your ECU may still think its -20 and a bavarian christmas time outside...

A functional temp gauge sensor (and gauge) will still move a bit from zero if its basically ok. A disconnected temp gauge sensor will not move at all.

From *what it sounds like*, your findings may be explained by a missing/permanently open thermostat. I have seen this when the engine overheats due to a bad viscous fan coupling. A simple fix for the unwary is to remove the thermostat, thus having maximum coolant flow, but no quick way to heat up the engine. I have bought a used, sick (as in unwell...) E28 with exactly this situation in the past.

If your cooling system (rad/pump) is still reasonably functional, it may not heat up to normal temp, thus be permanently "stuck" in full rich, cold start mode (ie full choke analogy with a carb). If you've never changed the thermostat since you've bought the car, now is a good time to. Its $20 dollars, 10mins and two/three? bolts to change.


You may have a perfect electrical system, with just one failed mechanical part (the thermostat). Either that, or you're up the creek, with only a multimeter for a paddle...

If youre scratching your head about changing the thermostat,
check the url for the haynes manual I posted in this thread.

Good luck, hope this works for you,

[kyM bMw]

thanks wally and ace =)

[ACE-E28]

yeh i have had broken Thermo stats on both my E28s...meant to mention it... If you replace it make sure you blled teh cooling system properly as well otherwise it will probably overheat.

[wally~e28]

If you decide to replace the fan, seriously consider installing an electric fan system rather than the viscous.

If a viscous fan fails, usually the first thing you know about it is the engine overheating/runing hot. It sounds the same, looks the same, just doesn't push air.

If a thermofan doesnt work YOU CAN'T HEAR IT and IT DOESNT SPIN. You can pick it up straight way.

I have a twin thermofan system on my e28: a pusher and a puller:
The puller is a twin speed, two thermoswitch (91+99). The pusher is a 91 (on at 91 degrees)
Both of them have a manual override so I can switch the fans on from a toggle switch on the dash. (yes I am paranoid, yes I have cooked a headgasket due to a failed viscous fan...)
My system was put together from the parts bin,
or most bits for this can be bought from a pick a part,

And as ACE rightly said, bleed the system too or you might soon have to learn how to change a head gasket....

[Rated M]

I once wondered why my car was using a lot of fuel.
A sneaky neighbour was helping himself to a little each second night. It took me a few weeks to twig then I slept in the back seat under a blanket.
He got a good surprise, when he saw my baseball bat he started to whimper. I mobiled the cops and tied him up until they came and got him 25 mins later. I was told I should not have threatened or tied him up. They did not believe me when I told them he asked me to tie him up and belt him if he tried to run?
Cops really don't believe anyone.
Back on topic... are you sure you don't have a leak or a local thief?

[Madhatter]

Really going to have to find out just how bad the mileage is, either by fixing your odometer or installing an aftermarket unit. The only alternative is to start replacing parts and having components tested, things like injector cleaning arent particulary cheap in the grand scheme of things