[E90DTM]

I jumped my car at high speeds and scraped pretty hardcore on the highway a few days ago when I hit this dip thing. I thought everything was fine until lights started flashing all over my board. Nothing came up until I lost most of my coolant but it was already too late then. The yellow temp light started to flash right after the low coolant light flashed. I pulled over as quickly as possible and shut the engine off when it let me around 15mph. I had to get the car towed (I had to take the bumper off and use 4x4s to get it on the flat bed ).

When I got it home I jacked it up and checked the damage. I guess I just scraped my bleeder plugs off of my radiator. I'm trying to find replacement plugs now and still need to do a compression test to see if I damaged the head.


My questions for you:

1. What's the cylinder compression supposed to be at?
2. What does that yellow temperature light exactly mean?
3. What temp does the engine have to reach for it to start flashing?
4. Isn't there a red one after it?

[IancoleTX]

1. 14.5:1
2. banana in the tailpipe
3. 800 F
4. no

[Gavin@MMW]

Originally Posted by E90DTM

I jumped my car at high speeds and scraped pretty hardcore on the highway a few days ago when I hit this dip thing. I thought everything was fine until lights started flashing all over my board. Nothing came up until I lost most of my coolant but it was already too late then. The yellow temp light started to flash right after the low coolant light flashed. I pulled over as quickly as possible and shut the engine off when it let me around 15mph. I had to get the car towed (I had to take the bumper off and use 4x4s to get it on the flat bed ).

When I got it home I jacked it up and checked the damage. I guess I just scraped my bleeder plugs off of my radiator. I'm trying to find replacement plugs now and still need to do a compression test to see if I damaged the head.


My questions for you:

1. What's the compression ratio of the n52?
2. What does that yellow temperature light exactly mean?
3. What temp does the engine have to reach for it to start flashing?
4. Isn't there a red one after it?

LOL Low and SLOW not low and FAST...

compression is 10.3:1 I think, that light means your way too hot (obviously) 250° or more IIRC, never seen a red one, and dont want too.


Edit: its 10.7:1

[koreez88]

With you car THAT low and flush, I don't see how you'd drive it fast, it's unsafe lol

[e90pilot]

I'm not sure about your car but I have for sure seen a red water temp warning light. It happened when my water pump died. The yellow one popped up quickly followed by the red light. According to the manual a yellow water temp warning light means slow down but you can still drive it, but a red one means you need to stop and shut it down.

As far as I undersand the n52 never holds a constant water temp. It changes based on certain parameters. A light means temp has fallen out of spec for the given situation.

[kevin@bavarianx]

Compression numbers should be close to each other also a leakdown test is a better way to check.

[rothwem]

Originally Posted by Craven 328

LOL Low and SLOW not low and FAST...

compression is 10.3:1 I think, that light means your way too hot (obviously) 250° or more IIRC, never seen a red one, and dont want too.


Edit: its 10.7:1

Your compression numbers are wrong, they're usually given in psi, i.e. 180 psi or something, its a measure of how much pressure the cylinder can hold to determine if there was damage to the head gasket or valve seats. Its called a compression test because a pressure sensor is put in place of the spark plug, then the starter is spun.

But with all that said, I still don't know what the compression numbers should be for the N52 engine...

[ddigangi]

Originally Posted by IancoleTX

1. 14.5:1
2. banana in the tailpipe
3. 800 F
4. no

funny you should say that

[bavarian19]

Originally Posted by ddigangi

funny you should say that