heya, went out to my Z today in minus 5, started it up and left it running to heat it up, started fine and sounded fine apart from a slightly squeeky belt. got it 2 minutes down the road and the hicas, battery, abs and lights warning lights all came on, pulled in and the car started acting up, wasnt firing properly and kept trying to stall. decided to go straight home and on my way the temp gauge started to rise, thankfully got it home fine and switched off, there were alot of bubbling noises other weird noises coming from it and a small drip of fluid from around the filler.....anyone have any ideas what has happened??? any help welcome...hate seeing the Z unhappy!! cheers paul

exactly that. thats why i would rather let it tick over with alittle oil in the top until warm then drive it with cold oil

You've got no oil at the top of the engine when starting from cold, the best way to get oil up there is to drive it. Oil won't get up to the top end as quickly if it's just sat at idle.

 

The oil is more viscous (resistance to pour) when cold. Engine on idle produces low oil pressure. So, you've got thick oil in a cold engine with no pressure. What's it not doing? It's not getting through the oil galleries properly and not getting up to the top end. Metal against metal! Oil doesn't really work until it's at operating temperature, meaning the more you just leave it idling doing nothing, the more wear you're creating. You need to get some heat into the oil, get it moving, quickest way to do that is to drive it gradually bringing the revs up.

 

Obviously don't get in it and thrash the nuts off it as you'll screw the turbos up and do damage to the internals. But light driving is the best way to warm the oil up and keeping the wear low.

 

Makes me laugh when I hear people leaving their car to warm up for 10 minutes or so thinking they're doing the car some good, when in actual fact, they are doing the complete reverse.

 

Si, you have a history of writing knowledgeable and well reasoned posts on the forum here. I, for one, enjoy your well thought replies and witty responses.

On this occassion however, I think you need to re-think what you've put.

 

A few facts which contradict your post:

1. Oil does not drain back into the sump - unless stood for many weeks, possibly months.

[A worn oil pump could allow this to happen though]

 

2. The oil pressure regulator takes care of start up pressure. Usually, in my Z for example, the pressure within a couple of seconds of start up will sit at 120psi until the oil starts to warm and thins a little (10W40 Mobil 1) - regardless of RPM.

[The regulator, if worn, could, depending on design, reduce this higher cold-starting pressure]

 

3. If you've got the right oil for the operating climate - cold oil is just as effective as warm oil. It's the oil pump which might have trouble pumping a sufficient amount of 'thicker' oil if you demanded it - e.g. taking your engine above 4K RPM.

 

4. Most engine damage occurs within the first few seconds - whilst the pressure comes up from 0. This is one of the few times metal-on-metal contact could happen. On a regularly driven car with good oil - it should be of no concern.

 

Excessive idlling will cause however:

- A build up of glaze in the bores

- Excessive carbon buildup in the heads.

 

Anyway, Si, I know we haven't spoken before, so please don't take it personally that I'm disputing your opinion. Like I said above, I usually enjoy reading your posts and replies, but felt this particular post of yours was more mis-information than information.

 

Constructive criticism welcome

Simon.

the oil pressure is taken from the block, not the heads.

So even if the oil pressure is high at the OPS, doesnt mean there is alot of oil in the heads, hence the comment :)

 

Yes, the oil pressure is taken from the block.

 

Oil only has its true properties once its up to temperature. The amount of work the engine has to do at idle (and therefore heat generated) is absolutely minimal so the engine will take forever and a day to get to operating temperature. While this is happening metal-metal contact is wearing all the bearing surfaces out.

 

Although pressure is low in a general sense around the engine. The oil pressure is actually higher when the oil is cold due to it not passing through the passages as easily but it is correct that the top end does get starved, due to poor flow from the oil being thicker.

 

It really is pointless and detrimental to the engine to sit there leaving it on idle to come up to temp. It's logic.

disagree

 

 

...

Words from the guru:

http://www.300zx.co.uk/forums/showpost.php?p=762996&postcount=30

 

 

And this is a the thread it came from:

http://www.300zx.co.uk/forums/showthread.php?t=50649&highlight=long+warm+car

 

I think what si is basically saying is its better to dry the car from cold than let it warm up stationary as it takes longer and this is when wear happens most.

Edited December 1, 200817 yr by j1mmytt

Si, you have a history of writing knowledgeable and well reasoned posts on the forum here. I, for one, enjoy your well thought replies and witty responses.

On this occassion however, I think you need to re-think what you've put.

 

A few facts which contradict your post:

1. Oil does not drain back into the sump - unless stood for many weeks, possibly months.

[A worn oil pump could allow this to happen though]

 

2. The oil pressure regulator takes care of start up pressure. Usually, in my Z for example, the pressure within a couple of seconds of start up will sit at 120psi until the oil starts to warm and thins a little (10W40 Mobil 1) - regardless of RPM.

[The regulator, if worn, could, depending on design, reduce this higher cold-starting pressure]

 

3. If you've got the right oil for the operating climate - cold oil is just as effective as warm oil. It's the oil pump which might have trouble pumping a sufficient amount of 'thicker' oil if you demanded it - e.g. taking your engine above 4K RPM.

 

4. Most engine damage occurs within the first few seconds - whilst the pressure comes up from 0. This is one of the few times metal-on-metal contact could happen. On a regularly driven car with good oil - it should be of no concern.

 

Excessive idlling will cause however:

- A build up of glaze in the bores

- Excessive carbon buildup in the heads.

 

Anyway, Si, I know we haven't spoken before, so please don't take it personally that I'm disputing your opinion. Like I said above, I usually enjoy reading your posts and replies, but felt this particular post of yours was more mis-information than information.

 

Constructive criticism welcome

Simon.

 

 

Hi mate. I have a few points to question your responses.

 

1) Agreed, not all oil does, but most of it does. Which is why taking dip-stick measurements is ideal on an engine that’s stood. You’ve got to wait for oil to flow back down to the bottom.

 

2) OPR does take care of flow, but only to bring pressure down on cold-start. It again does not have any capabilities in getting oil ‘flowing’ round the heads. The pressure maybe controlled, but the oil’s viscosity is still not at the best rate for flow.

 

3) All oils work best at operating temperatures regardless of weight and / or synthetic content. Synthetics are thinner at lower temperatures and don’t get much thinner at higher temperatures. In that respect, it’s just as well you get in the car and drive it as you’re almost contradicting the fact of putting that grade of oil in in the first place. :)

Edited December 1, 200817 yr by FunkySi

Ive also read in owner manuals that the car should be driven to warm up and not while stationary.

Modern cars don't need a warm-up proceedure. It's documented many times. Best thing is to drive it gently until the oil has reached its peak pressure.

so when i start my car from cold, why is the oil pressure up at 6.5 bar then when it comes up to running temp, the oil pressure has dropped to 3 bar?

 

the oil is thicker when cold hense more pressure in the system due to not being pushed round as easly but, there will always be some oil at the top. its never drained completely, you just dont get much freashly "sumped" oil getting up there until warm

 

 

Pressure does not effect flow rate when the engine is col. The reason the pressure is higher is because the oil cold and therefore thicker and has a harder resistance to pour...resulting in top end starvation.

Hi mate. I have a few points to question your responses.

 

1) Agreed, not all oil does, but most of it does. Which is why taking dip-stick measurements is ideal on an engine that’s stood. You’ve got to wait for oil to flow back down to the bottom.

 

2) OPR does take care of flow, but only to bring pressure down on cold-start. It again does not have any capabilities in getting oil ‘flowing’ round the heads. The pressure maybe controlled, but the oil’s viscosity is still not at the best rate for flow.

 

3) All oils work best at operating temperatures regardless of weight and / or synthetic content. Synthetics are thinner at lower temperatures and don’t get much thinner at higher temperatures. In that respect, it’s just as well you get in the car and drive it as you’re almost contradicting the fact of putting that grade of oil in in the first place. :)

 

Thanks for the reply. I think we may agree more than I'd given credit for:

1. Agreed. There is a lot of residual oil which drains back.

2. Agreed also, in my post I assumed that the engine is in good condition and the oil galleries are unblocked.

3. I would wholly agree if you said 'perform' better at working temp, as it's really the engine's ability (nee design) which inhibits full function at lower temps.

 

Just for the record, my start-up routine is usually:

- Start the engine

- Do the usual 'pre-flight' checks (check gauges, get belt on, set temp.)

- And I'm off - all in all about 20 seconds of sitting around.

 

Once I'm off, it's mainly conservative driving until I see the gauge read middle-ground and then I feel no guilt in using 'all that's available' :)

 

This F1 engine warm up should aid this thread:

http://uk.youtube.com/watch?v=56zbHewJHJE

 

Lots of middle revs followed by various blasts of high RPM.:

- Middle (not low) revs get the heat in quick

- Blasts of high RPM 'swells' the rings out so avoid glaze build up.

Trust me an f1 engine is far different to a modern car engine, They are pre heated before they are even started, they have hot water pumped thru the coolant and oil is also heated.

That video doesnt look like a warm up but more of a test or something exhibition maybe. Revving the tits off that while stationary cant be good.

Edited December 1, 200817 yr by j1mmytt

Trust me an f1 engine is far different to a modern car engine, They are pre heated before they are even started, they have hot water pumped thru the coolant and oil is also heated.

That video doesnt look like a warm up but more of a test or something exhibition maybe. Revving the tits off that while stationary cant be good.

 

Agreed, quite a different beast. But they are all warmed up - I haven't heard of the water being pre-heated before though(?)

Some may have seen these before, different cars, but same principle:

http://uk.youtube.com/watch?v=sf7DU4SZFF8

http://uk.youtube.com/watch?v=9nA6zoK5luE

http://uk.youtube.com/watch?v=jFLSfTZjlNk

http://uk.youtube.com/watch?v=Ys4ukHDIvZc

 

This one takes the biscuit however:

http://uk.youtube.com/watch?v=1JPBdBIFGNQ (from 58 secs)

Edited December 1, 200817 yr by WillyEd
Added links

Thanks for the reply. I think we may agree more than I'd given credit for:

1. Agreed. There is a lot of residual oil which drains back.

2. Agreed also, in my post I assumed that the engine is in good condition and the oil galleries are unblocked.

3. I would wholly agree if you said 'perform' better at working temp, as it's really the engine's ability (nee design) which inhibits full function at lower temps.

 

Just for the record, my start-up routine is usually:

- Start the engine

- Do the usual 'pre-flight' checks (check gauges, get belt on, set temp.)

- And I'm off - all in all about 20 seconds of sitting around.

 

Once I'm off, it's mainly conservative driving until I see the gauge read middle-ground and then I feel no guilt in using 'all that's available' :)

 

This F1 engine warm up should aid this thread:

http://uk.youtube.com/watch?v=56zbHewJHJE

 

Lots of middle revs followed by various blasts of high RPM.:

- Middle (not low) revs get the heat in quick

- Blasts of high RPM 'swells' the rings out so avoid glaze build up.

 

That's pretty much me in a nutshell. I did have to idle a little to get out of the garage, but thats about 20 - 30 seconds, by which time I am driving the car.

Thats another festival/exhibition an f1 car is never left to idle as it will just over heat very quickly, They used to shuv loads of dry ice in the vents to keep them cool at the start up and warm up laps not sure if they still do this tho. Warm up lap is mainly to heat tyres and brakes.

Thats another festival/exhibition an f1 car is never left to idle as it will just over heat very quickly, They used to shuv loads of dry ice in the vents to keep them cool at the start up and warm up laps not sure if they still do this tho. Warm up lap is mainly to heat tyres and brakes.

 

It is another festival car true, but it will be driven.

And true, it would, given time, over heat. But all the examples I posted are only being warmed for about 60 - 100 seconds. Seems a resonable amount of time to get a few litres of oil and several litres of coolant to about 90 degrees C.

 

I've seen the dry ice being used on the old turbo charged cars from long ago. They used to freeze the intercoolers - reversing any heat soak from being stationary.

Thats another festival/exhibition an f1 car is never left to idle as it will just over heat very quickly, They used to shuv loads of dry ice in the vents to keep them cool at the start up and warm up laps not sure if they still do this tho. Warm up lap is mainly to heat tyres and brakes.

 

No, They're not left to idle because they don't have any rad fans, so there is little cold air going through the radiator at standstill.

I agree you should not let your car idle for too long on the first start up in the morning,My old calibra used to sound like a bag of bolts in the first few seconds of starting in the morning and as i drove it she would go nice and quiet:D all the oil may not have drained too the sump overnight but there wont be much oil protecting the top end on start up& also driving off at a nice steady pace will warm up the gearbox & diff etc:D Hope that makes sense guys?

i hope the right anti freeze is in it, thats wat i thought may have caused it at first. took the car to the garage that it was serviced at and apparently the alternater isnt working the way it should, its only puting out 10v and so they recon this could be the cause of the problems. not sure about the driving car from cold theory as every car ive ever owned (especially this one) drives like a dog when driven cold. gearbox whines, engine feels and sounds rough...not nice! understand where your coming from tho....cheers everyone for advice