x5 ticking, mayo and sensor?
 

hi guys, im have a worrying ticking noice :confused:coming from the engine (i think) its there at start up but it can go away after 5-10 mins another times its all the time. its a bmw e53 3.0l petrol and its been fantastic the few years i had it and still love it:thumbup:

the ticking is very load but the car drives fine and has done since its started about a month ago. i had the aa out he hooked it up to the computer and said one of the lamba sersors was showing as a error? could this cause it? he also said it could be a valve flap sticking cos the are plastic? he said he wasnt really sure what was causing it but theses were his best thoughts.

i had it serviced last year and they said the air con belt needed doing, could this cause the ticking? also i found mayo in the oil cap:yikes:? sign of the head gasket??

i would normally take to bmw specialist but i have only just finished saving up to have it lpg and i know if i take it to the garage i can say goodbye to the system :rolleyes: that i really need with the fuel prices at the moment

any thoughts would be much appreciated, thanks jon:thumbup:

Symptom: The engine makes a ticking noise when running
likely cause: loose valve
a ticking noise is produced by the loose valve rattling against the rocker arm during operation.
The exhaust manifold may be loose, or check oil level and top it if needed be. If the oil level is correct, the ticking noise is likely happening because the oil pressure is low and consequently the upper engine is not getting fully lubricated. If the oil pressure is the problem, your dashboard oil light should come on. Good luck:thumbup:

If the ticking is half engine speed then as said earlier it might be from the valve train. If it goes away eventually then I would guess at a hydraulic tappet. If its more of a rattle then it could be the camchain tensioner (ignore this one at your peril, BMW cam chain guides are fragile), or a vanos unit. You need to try and pinpoint exactly where the noise is coming from on the engine

hi guy, thanks for the reply's, im going to try and put a video up (not great with comuters lol!) its more of a rattle than a ticking sound so i will investigate further and try and pinpoint exactly where the noise is coming from

The 'mayo' as you call it is an emulsion of oil and water. It is usually caused by condensation inside the engine, mixing with oil, and collecting over time. It happens due to short trips that don't get the engine hot enough, for a long enough period of time, to burn off the condensation. It typically shows up under the oil filler cap, and it can also collect in the oil separator valve/crankcase ventilation valve. The problem with that aspect of it is that because it has water in it, it can freeze. That is what leads to the famous oil separator problems.

The condensate can be cleaned out of the crankcase with one or more hot oil changes, fairly close together. If you are not able to give the vehicle a good run every now and then to burn off any collected condensate, you may want to move to a shorter oil change interval than the approximately 15,000 miles the vehicle calls for.

This will not clean out the OSV/CCV though. If that is partially or fully clogged, it needs to be taken off and cleaned out, and the lines checked.

Does the ticking get faster as the engine RPM increases?

Check You Tube for 'vanaos rattle' and see if that sounds like your engine