Car cranks but refuses to start...

[stevepoulter]

Hi guys, I'm new on this but it's seems like the place to be with more knowledgeable people.

I own a 2010 F10 520d with approx 90k.

This car has been perfect in the 8 years I have owned it, not one issue until recently.

I took it the car for a local drive, probably a 15 mile round trip. The fuel mileage remaining stated 20 miles and I thought I'd get to my destination and fill up when I get there. I don't know why but when I got there I decided to drive home and fill up when I got home as I had 25 litres of diesel in my garage in Jerry cans.

I got home no issues and the fuel distance said I had 3 miles remaining. I then poured in the 25 litres of diesel. This diesel was obtained just earlier in the day from Asda.

I then decided to pop out again and I started the car and drove approx 50 meters and the car just cut out. Since then it doesn't start up, cranks but will not start.

The vehicle is auto and it was stuck in the middle of the road refusing to get out of park, I managed to manually get it into neutral and got it back onto my drive.

This was over a week ago and it still won't start. This is what I have done so far....

I have ISTA and plugged this in, I got two errors

1) Rail pressure too low for engine start
2) Camshaft and Crankshaft no signal

(Not verbatim but I am not near my PC currently)

I checked the camshaft sensor and that is operating fine, signal voltage changing from 0v to 5v when a metal object placed nearby.

Crankshaft sensor I can't seem to work out. I understand the 3 pins have either GND - 5v SIGNAL - 5v POWER. I removed the sensor with the plug still attached and the readings were GND - 0v - 5v. When I removed the plug and tested the plug they were GND - 5v - 5v.

As I removed the sensor I would have thought that being away from a magnetic source (i.e. the crankshaft wheel cover) it should be in an OFF state and therefore the Signal pin should show 5v. Can anyone confirm this or is the OFF state 0v.

Fuel system

From my basic knowledge of ISTA I managed to work through the fuel troubleshooting program.

From what I can see I am getting 4.2bar (I am not sure of this as I'm not sure if I'm using ISTA correctly) pre fuel pressure but ZERO pressure at the high pressure fuel rail.

Tomorrow I will be checking the fuel lines, fuel filter.

Is there anything you guys could suggest to help me find the fault more quickly. Or anything obvious I have missed.

I am very grateful for any help.

[helix402]

ISTA has in depth guided troubleshooting procedures for all faults stored so it will guide you through the diagnosis procedure.

It can be long winded though and if you are experienced at diagnosing BMW faults you can sometimes diagnose faults quicker without it.

Re your car fault, it’s worth clearing all faults and seeing which ones return. Also make sure you have enough fuel in. You have the N47 which has many common faults including failed timing chains and high pressure fuel pumps amongst others.

Ista will also display a screen of actual against desired values for engine operating values which is handy do diagnosis.

[stevepoulter]

Thanks for the reply

I have cleared the codes and they do disappear. When you try cranking the engine only two codes re-appear.

Crankshaft Camshaft sensor no signal
Fuel rail pressure too low for engine start.

I am not very good with ISTA but I think I need to spend a day with the car and ISTA and work through it.

Car has been dead for a week and I don't get the time to REALLY get my hands dirty. Usual excuses, wife and kids in the way, etc. I am hoping to make time this weekend.

[stevepoulter]

The work through guide for the crankshaft sensor is OK, I just can't seem to find what voltage values I should have on the signal wire with an ON/OFF state.

Do you think it would be beneficial for me to purchase a fuel pressure measurement kit? I may do after this weekend after I have gone through the fuel hoses, fuel filter and fuel pressure to high pressure fuel pump.

I appreciate you input, I'm very grateful for anyone help

[helix402]

I’d try testing the cam and crank sensors another way, look at live data whilst cranking. If both sensors give a sensible reading-they’re ok.

If the cam chain is faulty, slipped/stretched/broken that would give cam/crank fault codes, if it has just slipped you would normally have cam/crank correlation fault code stored.

Re fuel pressure, I had this a code a while back on my 330d. Range said 20ish miles, car cut out would not restart. The fault code was fuel rail low pressure. It had run out of fuel.

I’d check your cam/crank sensors are working ok and you have enough fuel in the tank before going much further diagnosing things and buying fuel pressure gauges.

[Elliot2000]

If u have cam/crank fault, and rail pressure too low then I would put money on a snapped chain.
Take the oil cap off and get someone to crank the engine whilst I look inside - I should just about be able to see part of the cam shaft and a follower - if nothing moves while cranking then your chain is kaput .

The fuel thing might be coincidence

[stevepoulter]

Thanks for the input chaps. It is starting to look like timing chain,.I don't think it's snapped though I think the timing lost i.e. the chain has slipped some teeth. I think this because when it cranks it does so normally, not quicker that normal.

Slight update,

I managed to test fuel pressure and crankshaft/camshaft sensor synchronisation.

Pre fuel pressure is fine at 4.1bar
Fuel rail pressure is next to nothing fluctuating between 0-2.6bar

Crankshaft/Camshaft synchronisation fluctuates between Engine position cannot be determined (0) and Synchronisation OK (30) when cracking the vehicle.

I think I am going to attempt the chain change myself, I have got a quote from a local garage and the guy wants £3500. No way I'm paying that when the chain bits are like £400-£500

Unless you guys can recommend a garage in Birmingham, I'm willing to pay someone £1200 max.

Thanks once again

[Jaybmw]

You know it's dam near an engine out job on that. I seen someone doing it in situ but it looks hideous.. what makes you think timing is out ? You obviously checked the fuel pump yes? Simple things first, does it have a pick up ? The rail is not getting fuel I take it

[stevepoulter]

Yep aware of the work involved, gearbox out, flywheel off, oil sump off, injectors out, rocker cover off...the lot basically. Only thing putting me off is the only place I have to do the work is my driveway, in this cold. Garage is not big enough.

That's why I don't mind paying someone but it must be reasonable.

In regards to timing, the reading I'm getting through ISTA where Crank/Cam sync is fluctuating suggests timing has been lost.

I won't know for definate until I get the rocker cover off and gearbox out, then I can check the TDC points and calibration marks.

Why couldn't this happen in the summer!

[Elliot2000]

Is it manual or auto?

5 series probably the easiest n47 to do this job on because of the amount of space. Got an engine hoist? If it’s auto, support the gearbox on axle stands and unbolt bell housing and torque converter and lift the engine out. If it’s manual, u can still do this but lining up the shaft to flywheel is a bit more tricky and it’s probably easier pulling out the engine and gearbox in one and taking gearbox off once in the garage. Don’t bother trying to do the job in situ, makes everything harder.
U can get the engine ready to pull out in less than two hours and then u can work away in the garage rebuilding it.

Valves don’t always bend as the followers and cam carrier normally breaks first. If the valves are on then u don’t have to pull the head off, just sump and timing cover.

Replace the cam and fuel pump sprockets too- u can get the kits with all 3 chains, all guides, both tensioners, oil spray nozzle, gasket and sprockets from autodoc which is well worth it

U need timing tools to set everything up, u have marks to line one cam to the other, but no other marks to set it up by. U can get a set from eBay for about £20 that does the job

[stevepoulter]

Thanks Elliot, it is an Auto

I think that is my best option. Remove the engine and then I can work on it in the garage out of the cold with easier access

I haven't got a hoist but I don't mind buying one for the job, cheaper than £3500.

If you can recommend any garages in the midlands I don't mind paying someone, if not, I'm sure I can get it done at home. I'm in no rush as I have a company Van so don't desperately need the car on the road.

Where would I buy the kit you mentioned? Looking online but I want to be sure it's good quality.

Edit: Sorry just read Autodoc, looking now

Edited by stevepoulter on Friday 9th November 20:14

Edited by stevepoulter on Friday 9th November 20:24

[stevepoulter]

Autodoc has no stock currently on timing chain kits.

Found this though...

https://www.eurocarparts.com/ecp/c/BMW_5+Series_2....

Is that the full kit?

[Elliot2000]

Yeh that’s the one, don’t forget to use a discount code because that’s very expensive as it is.

This is the timing kit I purchased, it’s tight to fit on the cam and I need to file the edges down slightly to make it fit nicer but it’s great for the price

[stevepoulter]

That's again

I found this kit, would I need these extra bits



I can see it's out of stock but I've seen it available elsewhere

Edited by stevepoulter on Saturday 10th November 15:41

[4rephill]

I'm struggling to believe that the timing of the car failing to start, and the running out of fuel are simply coincidences - Especially as one of the issues is a lack of pressure in the high pressure side of the fuel system.

It also seems that it would be an incredible coincidence that the timing chain would snap, just after the car had run out of fuel (not impossible, but unlikely)

It seems far more logical to me for the issue to be either damage to the fuel system due to the tank running dry (fuel pump disintegrating due to a lack of fuel lubrication, causing pieces of metal to go into the high pressure fuel system perhaps?), or an air-lock in the fuel system.

If it were my car, I'd be looking at the fuel system before I started messing around with the timing chain.

[stevepoulter]

4rephill said:

I'm struggling to believe that the timing of the car failing to start, and the running out of fuel are simply coincidences - Especially as one of the issues is a lack of pressure in the high pressure side of the fuel system.

It also seems that it would be an incredible coincidence that the timing chain would snap, just after the car had run out of fuel (not impossible, but unlikely)

It seems far more logical to me for the issue to be either damage to the fuel system due to the tank running dry (fuel pump disintegrating due to a lack of fuel lubrication, causing pieces of metal to go into the high pressure fuel system perhaps?), or an air-lock in the fuel system.

If it were my car, I'd be looking at the fuel system before I started messing around with the timing chain.

Thanks for your reply.

The car didn't run out of fuel it was on 3 miles remaining when I parked it and I added 25 litres of diesel. Which I know is virtually run out.

I initially thought it was a fuel issue as it is cranking normally, i.e. not quicker due to no chain resistance.

But after trying to diagnose with ISTA and running fuel bleed on numerous occasions, fuel pump runs, I have gone off the fuel pump issue. Pre fuel supply pressure is fine but rail pressure is zero when cranking.

This plus the camshaft/crankshaft synchronisation being Out has lead me to the timing issue. I think it has lost timing rather than being a broken chain, there is no unusual noise when cranking.

I am however just a novice and this is my limited diagnosis.

Am I right in thinking that if the engine has lost timing the ECU will refuse engine start to protect the engine. If so, how does the ECU do this? Would it stop high pressure fuel delivery? Any ideas

[stevepoulter]

I have just been told by a mate about a local garage that specialises in engine reconditioning.

He said for £1400 they will collect the car, remove the engine and carry out the following:

COMPLETELY STRIP THE ENGINE AND PUT IT INTO A CHEMICAL TANK

REMOVE ENGINE FROM CHEMICAL TANK AND PUT IT IN A HOT WASH

FULLY RECONDITION THE HEAD. SKIM, PRESSURE TEST, RESEAT ALL VALVES AND REPLACE ANY DAMAGED ONE, FIT NEW VALVE STEAM SEALS

CHECK PISTONS FOR ANY MAJOR DAMAGE AND WEAR THEN FIT NEW PISTON RINGS

CHECK CONRODS FOR DAMAGE AND WEAR

CHECK AND POLISH THE CRANKSHAFT AND REGRIND IN NEEDED

FIT NEW MAIN BEARINGS AND BIG END BEARINGS

REBUILD ENGINES USING ALL GENUINE OE GASKETS AND SEALS

REPLACE TIMING CHAIN OR TIMING BELT WHICH EVER IS FITTED

TEST INJECTORS BEFORE REFITTING

CLEAN & CHECK TURBO INTERCOOLER

CLEAN AND CHECK TURBOS BEFORE REFITING

CLEAN DPF

REFIT ENGINE TO VEHICLE

ALL NEW OIL AND FIT NEW OIL FILTER

DD NEW COOLANT

They are on EBay, anyone have any experience of this kind of service.

[Elliot2000]

Fuel pump fails to provide pressure as it’s run off of the timing chain. With cam and crank fault codes I’m fairly confident I have a snapped chain but u can confirm yourself, as I said, by having someone cranking the engine while u are looking I. The oil filler cap - if the cams ain’t turning and followers aren’t moving then u know the top end is no longer connected to the bottom end.

The only extra tools in the £60 kit is a crank handle and a socket by the loooks of it- not really needed

[stevepoulter]

Thanks Elliot,

Yes I remember you stating that and I completely forgot to do it, will definitely tomorrow.

So that kit is not worth the extra money, fair enough.

What do you think of this service the company provides? Any knowledge or experience of this kind of service.

In regards to cranking the engine, if the chain has broken would it do further harm if I continue to crank the vehicle, i.e. any more damage than already been done.

Thanks again for the input everyone

[Elliot2000]

If that firm does everything they say they are going to do for that price then I will be surprised.
I have heard quite a few stories of companies like that bodgingg engines back together or once they have the car and engine out - the prices suddenly sores up because of extras not covered on the original quote. So be careful- I’d do some research on the business.