Pinking in this heat (what else!!)

[braveheart]

Chaps i know this is an old one but my 350i is a pig when warmed up and pinks through out the rev range i know it could be fuel , pressure, or timing but it does seem to be temperature related.The gauge runs 80-85 all day but from cold it doesn`t pink.Do i need much improved cooling or what? Any comments would be appreciated.

[shpub]

Pinking is also related to the incoming air temp. So surprise surprise, many cars that never pinked probably are because of the heat. Not a lot you can do without major bodywork surgery. Could be worth retarding the ignition or just being careful and using Optimax.

[kjr]

Is this a summer only problem or is it all year round?

If all year round then this MAY be caused by using a thin oil which has got past the rings on the pistons and onto the heads. This causes a carbon build up. When the carbon gets hot it pre-ignites the fuel causing pinking. Check to see if you have got very oily/suity(sp) spark plugs.

I had this problem on my 400se and ended up getting new pistons and the heads decoked.

KJR

[RAW-SEWedge]

Must admit that I’m going a bit pink in the heat too

[white]

My 350i is also plagued by pinking so I know how infuriating it is (imagine being scared to accelerate in a TVR!) With mine it's definitely temp related- after trying Optimax which made little difference I bridged the otter switch with a paperclip to run the fan permanently- no more pinking....until after 1/2 an hour the fan ground to a halt (the bearings in these big Australian fans are crap!!!) After finding a new fan I've admitted defeat for now and disconnected the vac advance to the distributor. Later I think I'll try a 3 core radiator and putting the air filter in front of the radiator (Question regarding hydraulicing the engine- isn't the Griffiths air intake in the nose cone?)

[shpub]

Yes the air filter is but it is high up. The problem with the nose cone is access. There is not a simple way to get a 80mm pipe to the front. I would not recommend using the lower front spoiler because of the risk of water ingress.

[HeyAndy]

My car pinks too - though since i've been my fan constantly doesn't do it so much. The thing that baffles me though, that my Series 1 never pinked at all.

I'd be really interested in upgrading my rad to a 3 core and movining the filter too. Some info on this would be worth having.

[danny hoffman]

3 core is the way to go in my experience

[HeyAndy]

What is the difference between a standard rad and a 3 core? I've been having some trouble of late. My car hasn't overheated as such. Yet when I hit 4000 revs the temp will rise into the red whilst on the move and will not drop. Even when the fan is on.

Today I removed the thermostat went for a road test and whilst on the move the temp never seemed to drop but it also never climbed either when i hit 4k revs. Though when i left the fan running once stationary the temp did drop but not far enough! I'm suspecting a blocked rad and will consider overhauling the whole cooling system in the winter and will recon to a 3 core and a kenlowe set up.

Any ideas?

[danny hoffman]

The 3 core has more surface area (and I presume more water capacity) which gives more cooling. My 350 has twin fans and they were on most of the time before I got my rad rebuilt and upgraded (£150 at my local Serc Martson). Now they rarely turn on, I have done about 40 miles today in and around NW London and they didn't come on once.

I have a fan overide switch which I use if I think I am going to get stuck in traffic for more than about 5 mins as the temp then rises to 90 degrees (normally 80) and the fans struggle to get it back down - but it nevers gets any hotter than that.

BT my otter switch went wrong a few months back and the fans started cutting in before the car warmed up, although this sounds like a good thing, the ECU seemed to be getting confused as the car never reached 80 degrees and it wouldn't run properly.

Danny