How much did I save?

[IanA]

I've been having intermittent starting problems with my 2.8. It was even dollied home by an AA man when it failed after an 8mile run from home to a spares shop.

My C110 scanner consistently showed an exhaust cam position sensor error. Clearing that allowed it to start.

So I went out to the Z300S this morning and it would not start. I'd researched exhaust cam position sensors and their price range from £25 to £152. I cleaned up around the existing one- it's easy to get at on the front of the engine. I removed it and gave it a good go with WD40 and got it very clean. I replaced it and the engine started. Having been out for the day in another car, upon my return I tried- it started again. This could be a fix. I think if I'd got it to a BMW dealer they would have replaced the sensor regardless and charged about £300 for the OBD scanner diagnostic, full price sensor and labour to fit. Phew!!! And so much for the AA man's diagnosis of a fuel problem... (I didn't have my scanner with me.)

 

[t-tony]

Hope you have found, and cured, the problem. However chickens and counting spring to mind. If you do find that you have to replace the sensor buy a genuine one not a cheap replacement from eBay or Amazon, because you will soon be buying another.

Tony.

 

[IanA]

I take your point, Tony. I don't think that cleaning the sensor itself solved the problem. More likely is that cleaning and exercising the electrical plug/socket connection was the real cure. My point is that a simple maintenance/cleaning activity based on the OBD scanner evidence has renewed confidence in the car, saved me money and taught me to keep a scanner on board.

 

[NZ00Z3]

As an aside. If the exhaust cam sensor had oil in the electrical connector, then that's a cause for concern.

In the E46 forums, we are starting to see too many cases of cracked sensors letting though coolant or oil to their connectors and tracking up the wires to the DME pins. Coolant corrodes the pins and the DME need to be replaced. Oil shorts things out and causes engine fuel trim control havoc.

If you have this problem, change the sensor before the coolant/oil gets to the DME.

 

[t-tony]

Some Mercedes models have had similar faults for a good few years.

Tony.

 

[IanA]

Interesting... the detector end on mine looked sound but the D shaped surround was cracked. I've ordered a replacement.

 

[mrscalex]

Interesting... the detector end on mine looked sound but the D shaped surround was cracked. I've ordered a replacement.

Replacement is sensible. I hope you saw @t-tony advice and bought OEM or known good quality one. Success rate with cheap replacements is low. If you don’t want to spend the money secondhand original is preferable.

 

[IanA]

Chickens duly counted... not starting again today without clearing error codes. Closer inspection of the plug cabling shows a broken wire. I've contacted one of our on-site spares providers.

 

[mrscalex]

Plugs will normally dismantle. Sometimes they need a release pin. Personally I’d prefer to do it that way and start a replacement length of the right colour from inside. What you have there is too short to solder. Rather than graft a replacement on with 3 visible joins.

I have 2 old looms I can look for the plug on if required. But I’m away and I’m rarely quick even then

 

[mrscalex]

Mind you. Me being pernickety me…

I think that plug is on a separate engine loom that plugs into the main loom. So I’d replace that just because I can, ie I have a couple of spares. I can solder fine. But I hate seeing joins even with a tidy heat shrink on it.

Just some options for you.

 

[IanA]

The saga continues- I've been able to order a new replacement plug from Pantri Trading.

 

[mrscalex]

The saga continues- I've been able to order a new replacement plug from Pantri Trading.

Tip - Pantri trading are usually very expensive. Typically 3x dealer. Since BMW only supply spares to dealers Pantri must just be taking orders, going off to BMW to buy and adding margin.

BMW are not usually expensive on small parts like this.

 

[IanA]

Point noted.
TBH I was just pleased to be able to obtain this part.

 

[t-tony]

Glad you have found a “solid” fault Ian, this should finally nail the problem once and for all.

Tony.

 

[IanA]

£8.56 delivered from Pantri. £9.05 delivered from BMW.

 

[GZed]

£8.56 delivered from Pantri. £9.05 delivered from BMW.

So in answer to your original question: 49p

 

[IanA]

I'll try not to let it change my life.
Getting a reliable Z3 will do that.

 

[mrscalex]

I'll try not to let it change my life.
Getting a reliable Z3 will do that.

It's still sound advice for those happy to go along to their local BMW dealer. By way of example connector 61131378414.

https://www.ebay.co.uk/itm/293379173957 - Pantri £9.27 delivered.

BMW dealer - £2.50 collected.

 

[IanA]

Finale:
Received replacement plug BMW Wiring Cable Plug Connector Terminal Housing 3-Pole 12521433917
Received 3of replacement wiring/terminals BMW Wiring Connector Plug Terminal Repair Contact Pin 12520143433
Retained original exhaust cam position sensor. Put new replacement sensor in onboard toolbox
Assembled plug shell and new wires (replaced too-large poly grommets with correct size for plug)
Made 3 three new wires onto existing loom- soldered, heatshrink sleeved & taped.
Plugged in new connector
Started engine OK.
Stopped engine, connected C110 scanner & cleared all codes.
Started engine, drove 8 mixed miles of 30mph and dual carriageway.
Stopped engine
Checked OBD with C110 scanner. Previous error codes absent.
Result!!!