Do you have mechanical knowledge? Help me with a car mystery please.

**Maki** · 14th September 2009, 20:17

My car behaves in a way that seems inexplicable. I would be most grateful to anyone who can make sense of what it does.

It is a Nissan Primera 1990 2.0 automatic.

It runs fine and almost always starts. The only time it gives me any grief is if I have started it cold, moved it a few metres, turned it off, left it for a while (hours or days) and then tried to start it again. It hates this and it will take quite a long time turning the engine over before it starts and then it runs very badly until it warms up slightly.

Do any of you people with mechanical knowledge understand what is going on here?

Bling will be awarded for a good answer.

**Virago** · 14th September 2009, 20:20

When it does it, does the motor sound "different" when cranking over on the starter?

**cs363** · 14th September 2009, 20:20

My first guess would be dodgy coolant sensor.

**YellowDog** · 14th September 2009, 20:26

It sounds like a thermostat/auto choke issue.

**Conquiztador** · 14th September 2009, 20:28

Typical flux capacitor problem (The Korean ones). Only solution is to push the car back to the initial spot and it will start straight away. It has to do with the inferior quality of the Asian metal that is very sensitive to the earths magnetic poles.

**Usarka** · 14th September 2009, 20:31

Happened to a mate of mine in his subaru.

Something along the lines of an auto-choke type system flooding the engine because it was turned off too quick.

Might be a starting point (excuse the pun).....

**mashman** · 14th September 2009, 20:33

Could just be a lazy spark plug telling you to fuck off and let him sleep in on such a cold day...

**Virago** · 14th September 2009, 20:35

It sounds like a classic case of "valve lock".

I understand that the 2.0l Nissan motor uses hydraulic valve lifters. If started from cold and then turned off straight away before the engine oil has warmed, the valves can stick open. This prevents cylinder compression, and the motor won't start. When cranking over, the lack of compression is quite audible.

It's a bloody annoying quirk. It can be managed to a certain degree by regular oil changes, using the correct (10W/30) oil. The only real solution - don't start it from cold and then turn it off immediately. Always run it for a couple of minutes.

No, I'm not a mechanic - but I've got a 2.0l Bluebird...

**Maki** · 14th September 2009, 20:36

Originally Posted by Virago

When it does it, does the motor sound "different" when cranking over on the starter?

Yes, its sounds weak and wheezy, not like normal when it turns over more strongly.

**Maki** · 14th September 2009, 20:37

Originally Posted by Virago

It sounds like a classic case of "valve lock".

Brilliant, genius. Bling awarded. Amazing how fast that got answered.

**Virago** · 14th September 2009, 20:38

Originally Posted by Maki

Yes, its sounds weak and wheezy, not like normal when it turns over more strongly.

Okay, see my post above...

**cs363** · 14th September 2009, 20:55

Just for clarification, what series engine does your car have?

Nissan make quite a few 2.0 litre engines, is it a twin cam or single cam?

**Maki** · 14th September 2009, 21:03

Twin cam. I am sure the car has the top of the line engine for 1990.

Virago's explanation makes perfect sense because the engine feels like it has no compression.

**KrazyGixxerBoy** · 14th September 2009, 21:36

Originally Posted by Virago

It sounds like a classic case of "valve lock".

I understand that the 2.0l Nissan motor uses hydraulic valve lifters. If started from cold and then turned off straight away before the engine oil has warmed, the valves can stick open. This prevents cylinder compression, and the motor won't start. When cranking over, the lack of compression is quite audible.

It's a bloody annoying quirk. It can be managed to a certain degree by regular oil changes, using the correct (10W/30) oil. The only real solution - don't start it from cold and then turn it off immediately. Always run it for a couple of minutes.

No, I'm not a mechanic - but I've got a 2.0l Bluebird...

Yeah, what he said! I had similar issues with my Primera in the past....got rid of it and bought a Mitsi!