I am experiencing an unusual problem with my 2006 S-TYPE R. and hoping for some input or suggestions.

It has recently started having issues starting from cold.

I will try to provide as much info as possible, apologies for the long post:



When turning the key, sometimes nothing happens, sometimes there is a mechanical 'clunk', sometimes it tries to turn over and occasionally, it starts.

Repeated attempts eventually get it to start, when it eventually does, it just starts as normal as soon as I turn the key, rather than turning over for ages.

Sometimes after it starts, it seems to run 'lumpy' for a while, other times it is as smooth as usual.



Battery is brand new and charged, I replaced the battery negative cable as a precaution, as the terminal clamp had 'cracked' (the fault was there prior to replacing the cable, doesn't seem to have made things better or worse)

The flap on the ignition barrel isn't sticking open, when I insert the key, the seat and steering wheel move to the memorised position.

The dashboard lights come on when I turn the key to the appropriate position.


Reading the fault codes after trying to start it reveal P0340 and P0345, which are camshaft position sensors for bank 1 and bank 2 (or wiring ?)

It has been suggested that it is very unlikely that both sensors have failed at the same time, more likely to be a common issue affecting both banks (possibly poor earth / grounding ?)

Once it has warmed up, it will repeatedly start on the first turn of the key.

A friend suggested connect a jump lead from a metal point on the engine to a good earth, to see if the engine earth strap was loose.

Thought that this had identified the issue when I tried it yesterday, as it subsequently started at least six times in a row (removed the key, locked the car, unlocked it, key in ignition, started first time)

It appears as though this wasn't the case, was only starting because I had already had it running, so must have warmed up enough.

Left it overnight, tried to start this morning and it didn't even try to turn over, immediately tried the jump lead trick but still wouldn't start (unless of course I wasn't getting a good connection at one end ?)

I think that at one point I have also seen a 'coolant temperature sensor' fault code, but it seems to warm up as normal, doesn't overheat or loose water.


So, poor earth, sticking starter motor or relay, faulty coolant sensor, ley lines, ancient astronauts, car parked on ancient native American burial ground, or none of the above ?

 

most comnon is starter solenoid contacts worn out

 

Thanks for the input, I will investigate further

 

Just tried swapping over the starter motor relay in the fusebox under the bonnet (R20 if the online diagrams for a 2006 model are correct)



Exchanged it for the identical relay for the headlamp power wash (using the theory that this relay will not have performed as many switching operations)



Still took 5 attempts to start.



As an experiment, switched off immediately, removed the key, locked the car and it restarted first turn, repeated this a few times.



This suggests that my theory that the issue might be temperature related is incorrect (only previously tried restarts when the car has warmed up)

 

I am beginning to suspect the starter motor might be the culprit.


I found the 'engine earth strap', unfortunately not quite what I was expecting.

It seems to be just a single wire that appears out of the rest of the loom, only around four inches of cable with an eyelet on the end, bolted to the front of (UK) drivers side cylinder head.

Pain in the neck to get to it properly but using my inspection camera and following the wire to the bolt, everything feels okay, no exposed wire that I can see, bolt seems tight.



I would like to inspect the + and - cables going to the starter motor as well, but can't get the car high enough in the air by the roadside to remove the undertray. Looks like taking it in to work and putting it on a ramp might be the best option.

No idea where the starter motor even is !

Presumably where the gearbox meets the block ?

Did wonder whether the starter motor could be sticking or not engaging properly (solenoid issues ?)

If it's the same age and mileage as the car, (2006 and 176,000 miles !), it might be due for a replacement ?

 

The stater motor is on passenger side where the trans and engine meet as you said. One bolt is fairly easy. The other is kind of hidden. I thought i had to replace my starter once and thank goodness it was a bad battery in the end because the hidden bolt was going to be a job it looked like. Up on big jackstands or a lift is the way to go. I dont think ramps are high enough to get working space. They are to see your starter i believe to give you an idea. Check for a possible oil leak running into the starter. I have had that problem on other vehicles. At least if you get it off you can bench test if you wanted. Any member that has removed a starter on the 4.2 R models should have a tip or two i would think for that hidden bolt. Best of luck

 

Thank you !

Being from the UK, when I say putting it on 'a ramp', I mean a 2 or 4 post lift

Sorry for causing confusion !

 

no worries. Appreciate the clear up. That is the best way of all. On a lift. Being right hand drive i assume, i do not know for positive if the starter is still on passenger side. I quick read a couple posts about the hard bolt and it sounded bearish but doable with the right tools

 

Not to bust your behind, but can you please elaborate on "it tried to turn over"? Specifically, what is the starter speed like? It is normal and healthy, consistenly spinning the crankshaft at a good clip? Or is it slow and struggling? Or is the starter speed sometimes good and other times slow?

Since you also mentioned "turning over for ages", my hunch is you have two faults present. Something important to keep in mind while troubleshooting: Two vital things have to happen in sequence for an engine start.

1) First, the starter system (note I said "system", not just "starter") has to get the crankshaft spinning at the proper speed.

2) Next, fuel and ignition must be present for the engine to transition to running on its own without the starter.

I deal with a lot of older vehicles on other forums, and see many queries about an engine that "won't start". We then have to ask for clarification if the starter system worked properly. If the crankshaft won't spin up to the proper speed, that's one problem. If the starter system is operating properly, but the engine still won't run, then you're looking at a fuel or ignition problem. These are entirely different troubleshooting scenarios, so it's very important to know where you stand. No point in messing with the fuel injection or changing spark plugs until you first get the starter system in proper working order.

If indeed you have two issues present, we'll need to sort out the starter first and then work on whatever else is going on.

For now, I would suggest taking a voltage reading directly on the battery terminals while a helper turns the key to start. I want to see how the battery responds under load. Even with a new battery, there's a reasonable chance it can't supply the massive flow of electrons demanded by the starter. If so, voltage will drop off dramatically. It may even recover once the load is removed, so measure while you try to engage the starter.


One possibility is flooding, which washes oil from the cylinder walls and momentarily reduces compression. Once the engine does run on its own, it takes a few minutes to clear the excess fuel and restore normal compression. One big clue is the starter speed is higher than normal due to lower compression.

If flooding is suspected, try holding the gas pedal to the floor while cranking. Not positive about Jaguar, but on most fuel injected cars, this is a special mode to help clear flooding by switching off the injectors until you release the pedal again.



One important caveat about OBD codes and a no-start condition: The OBD II system is designed primarily for monitoring and reporting faults related to emissions. If you have a fault preventing the engine from starting, in the OBD II mindset, that's not related to emissions. Even if the computer knows why the engine won't start (a required input is missing or invalid, for example), it won't tell you via the OBD II interface. It's kinda like getting in the wrong line at the DMV office. Even though the slug lady behind the counter can access the entire computer system from any terminal, you wanted a new driver's license but are in the line for renewing vehicle registration. She crosses her arms and isn't going to offer the information you need:



Also, there is an interesting quirk with the CKP (crankshaft) sensor. If not sending a valid signal for engine start, typically nothing gets reported, at least right away. (See my comments above about being in the wrong line at the DMV.) There is a note in the OBD codes here about the CKP sensor:

JagRepair.com - Jaguar Repair Information Resource

From the horse's mouth, for code P0355:

"If CKP Sensor fault exists, engine will start after approximately 5 seconds of cranking as the ECM will default to CMP Sensor 1 signal for synchronization."

How long are you cranking the starter when the engine won't run? If the CKP sensor was acting up, and you were trying to be nice to the starter, you could theoretically crank the starter for 4.9 seconds time after time and the engine would never run.

 

I do not believe that is the main ground between the engine block and chassis. Because this ground cable has to handle the massive load of the starter, it should be similar in size to the cables at the battery.

The ground you found is for the engine harness itself. Near the bottom of this page, open the workshop manual and scroll down to page 1015 of the huge PDF.

JagRepair.com - Jaguar Repair Information Resource

Item #1 matches your description:



If you open the wiring diagram, near the top of that same link, do a Control-F search for "PI51". (That's the letters P and I followed by 51, not P followed by the number 151.) In figure 03.4, you will see this PI51 ground illustrated to the right of the ignition coils. Not a lot of current passing through there, so this ground wire is fairly small.

For the ground between the engine block and chassis, search for "ST2" and look at figure 02.2. That is likely a heavier cable running directly between the starter and chassis. In the text on the page above the diagram, the location is listed as "ENGINE COMPARTMENT, BEHIND LH WHEEL ARCH LINER" but I believe the side is incorrect, since the starter is on the RH side of the car (viewed looking forward). Furthermore, scroll up to page 19 for the ground point locations. ST2 is illustrated on the RH side, which makes more sense.

It would be worthwhile to check the presence and condition of this cable. If the engine has ever been removed, items like this often get overlooked during installation. It may be sitting there disconnected, or it may be missing entirely.




This video shows the location and removal details. I presume your 2006 will be the same:

 

Thank you for all the advice, information and suggestions.

The earth cable that I located is the one labelled #1, I thought that it looked a bit feeble to be the main earth from the engine block.

To clarify, when I say it 'tries to turn over', I mean there is a mechanical 'jolt' when I turn the key.

The engine doesn't keep cranking, like it does when you are trying to start with a weak battery or no fuel supply.

When it does actually start with a turn of the key, it is almost instant, no prolonged engine cranking.

Next move is to get it on the lift and remove the undertray to be able to see the starter motor and cables.

 

Thanks for the clarification. To make sure I understand the situation correctly: Sometimes the starter responds normally when you turn the key, and the engine starts quickly. Other times, you just get a clunk or noise from under the hood but the crankshaft is not turning. Is this correct?

How reliably can you duplicate the fault?

Earlier you mentioned swapping the starter relay with another position. Good idea, even if it didn't help. Give the original relay a good visual inspection. Specifically, look for signs of heat discoloration on the prongs. If the original relay was wearing out, the internal contacts get hot due to a marginal connection. This heat gets transferred to the sockets in the fuse panel, leading to oxidation and the metal losing its spring tension. To test the sockets for proper grip, get some sheet metal the same thickness as the relay prongs, and cut it to the same width. Test each socket individually, to make sure the grip is still strong. It's important to test the sockets one by one. If only one was failed, and you tested them all at the same time using the relay itself, you'd never know if just one was loose.

After that, I'd inspect the starter megafuse. This is a massive 400A fuse in the trunk, outboard and forward of the battery. This thread shows the location behind the liner:

https://www.jaguarforums.com/forum/s...-issue-230037/

In that thread, the problem was with the adjacent 250A fuse that feeds the rest of the car, but the general idea is the same.

Next, I'd check the charging system with a voltage reading directly at the battery posts. The charging system shares the same cables and ground feeding the starter, so it's a handy test of their general condition. Your car has a "smart" charging system where you'll see approximately 14.5V right after start, tapering down around 13.7V after a few minutes. Remember, take the reading directly on the battery posts, not the terminal ends.

If all those tests are okay, you're probably looking at a starter on its last legs.

 

Thanks Karl, your summary is spot on.

Either flawless start immediately on the key, or a clunk / noise and then repeated attempts with the same result until it suddenly starts.

Probably 1 time in 10, it starts straight away when left overnight, the other 9 times take repeated attempts.

After it has started once, it appears to then start immediately several times in a row.

I had a look at the starter relay when I swapped it over, no signs of heat damage / discolouration on the pins or the sockets they plug into.

For the cost of a re-manufactured starter motor, I have decided to risk it and ordered one 'just in case'

I just need to get some free time to take it into work on my day off and 'borrow' a lift for a while

 

Shop carefully for any replacement starter, whether new or reman. There is a LOT of junk out there. This is truly one of those situations where you get what you pay for. If your local discount parts chain offers a $79 starter with a lifetime warranty, do yourself a YUGE favor. Run away screaming and don't look back.

Starters by their very design eventually wear out, so a lifetime warranty is just a marketing gimmick. The business model for remanufactured units from a discount chain? A fresh coat of spray paint, new brushes if you're lucky, a spiffy cardboard box, and the high probability you'll lose the receipt. If new, expect low quality Fling Dung or Wok Hoam brand shipped all the way from China. Either way, the business model should also include a slanted dispenser rack with rollers, similar to how milk jugs are sold in a big grocery store. This makes it easier on the poor kid behind the counter who keeps handing you equally worthless replacements.

Given the chance to spend your time and money, I'd highly recommend shopping where professionals get their parts, such as NAPA or CarQuest. Be careful, as some outfits try to compete on price with the discount chains and also offer a less expensive lower quality version. Even though it won't be cheap, spring for the top of the line offering with a more realistic warranty, ten years for example.

And definitely run the quick voltage checks I suggested earlier. One is for the battery under load (where it really matters) and the other covers the charging system which conveniently checks all the cables. Maybe ten minutes tops with a voltmeter. These are some VERY basic checks, similar to how the doctor always checks your temperature and blood pressure even if there for a sore knee.

 

I think there is some confusion?
The starter relay is NOT the same as the starter solenoid. Have you replaced the starter solenoid?
Sometimes they only come with a new starter too.

I think your next step is to replace the starter. Listen to Karl's advice above on where you get it.
After all the trouble I have had in the past with stuff like this. I really prefer to have my original OEM unit rebuilt if possible.
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I figured that the solenoid would be part of the motor assembly, couldn't find a parts reference for it separately.

The starter motor I have ordered is from a UK company who specialise in rebuilding starters and alternators.

Selling for 10 years+, 22k+ feedback.

Their description states:
“Fully Remanufactured to OE Quality from an original DENSO core, not an aftermarket or foreign unit”
This unit has been fully stripped down, cleaned, shot blasted and rebuilt with 100% new bearings along with other new parts as required to be rebuilt to as new and tested to OE standard.

I will see what I think when it arrives.

 

I think you getting a rebuilt denso is money in the bank. Dealing with heavy equipment starters all my life gave me a firsthand look at differences between oem and aftermarket. Mostly they show up in the stator and the relationship between the starter bendix and flywheel ring gear that ultimately is influenced by the starter housing being made right on the money or good enough to pass QC

 

Yes glad to hear it's rebuilt on an OEM core. Just too many problems with after market starters and alternators. We have dozens of threads about it.
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solenoid contacts wear out like 10 times before the motor does. you can get them i forgot where though

 

New starter is due next week, I will add some notes when it arrives.