Oil Change Advice Needed

[starman]

When first starting an engine after an oil and filter change it takes a while for the oil pressure warning light to go out as the oil filter has to be filled up before oil gets to the bearings.

I have never liked this and on all of my previous cars (and there have been a few) I would prevent the engine from starting by removing the lead from the coil. I then let the oil get pumped around as the engine spins on the starter motor. None of those cars had engine managment of any kind unlike the Rav.

Would doing the same on the Rav damage anything on the engine management side?

What do other people do in this situation?

Thanks

Dave

[bothwell_buyer]

When first starting an engine after an oil and filter change it takes a while for the oil pressure warning light to go out as the oil filter has to be filled up before oil gets to the bearings.

I have never liked this and on all of my previous cars (and there have been a few) I would prevent the engine from starting by removing the lead from the coil. I then let the oil get pumped around as the engine spins on the starter motor. None of those cars had engine managment of any kind unlike the Rav.

Would doing the same on the Rav damage anything on the engine management side?

What do other people do in this situation?

Thanks

Dave

On the 4.1, I can't see any reason why the ecu would become confused if you just turned over the engine without starting it - ie removing the coil lead. Indeed, its one way of disabling the car easily if you don't want it nicked!!

So what you're suggesting seems a good idea. I've heard of folk filling the filter before fitting the new one, but it all depends on its position and angle.

Once the ht lead is reconnected then it should fire up right away. I know that some ecu's programme themselves to the engines idiosyncrasies but I suspect that the ecu in the 4.1 isn't that clever. Remember that the ecu for the 4.1 RAV would have been designed well before the production dates in 1994. As for later versions, I couldn't say.

[anchorman]

I agree with bothy, there should be no problem with the engine management. To prime the oil properly the spark plugs should be removed to take the load off the crank but this is normally after an engine overhaul.

Having said that I have done thousands of oil changes and a lot on cars that have done astronomic mileages. I honestly wouldn't bother with the measures you are suggesting. The crank remains full of oil during an oil change and trust me the oil doesn't drain from the crank bearings for a very long time - days or weeks. Any rumbling is usually from the hydraulic gear on the camshaft and they soon fill up. Modern oil will find its way around the engine long before any damage is done (within the design parameters of the engine). Just start it and allow it to idle while the light goes out and you will do no harm.

I'm of the old school and can remember when tolerances where so poor that oil could quickly run back but these modern engines - especially Toyota engines are so well made the oil won't run back.

However if it makes you feel better!

Cheers

[shcm]

It's been years since I worked on EMS and even then it is hardware, none of this nasty production software nonsense. :D

I expect the EMS will "know" that the engine is being cranked for a long period and not firing, because the engine speed signal will probably be at a lower frequency for a longer period of time, than it would be if the engine had fired and was idling. I doubt it take any notice though. So almost certainly no problems.

Depending on how the thing works, you might be changing the effective load on the coil drive stage in the ECU, but they are usually very rugged, (they have to be). We try to make 'em "bloke with big oily spanner" proof.

As bothy says, it was probably designed in 1847, 100 years before the bipolar transistor.

Me too, I just wait for the light to go out after an oil change, but then I'm just a very amateur mechy with a very very tiny oily spanner, although my soldering iron is enormous. :D. Actually, that's not true. These days it is very small and I have to use a microscope :P :D.

[starman]

Thanks for the reassurances that no damage will be done. It probably is a case of me being over cautious but I've always done it and I'm too old to change my ways now. :)