Some background, I'm new the land rovers. Just picked up my first, a 2011 lr4 HSE lux, with 138k miles, and the 5.0 V8...not sure I need to say that since it's the only engine. Anyway, I have been doing preventative maintenance, latest of which is the coolant crossover pipes.

The car has been driving great for the past few weeks, the length of my ownership.

The problem:
Car cranks, but doesn't start.

The cause:
I replaced both front and rear coolant crossover pipes.

Details:
I completed the work yesterday, and the car barely started. It had a very rough start and idled high. I realized I forgot to plug in the connector at the bottom back of the intake manifold. No idea what it is, if someone knows I'd like to know.

Today I unbolted the intake manifold partially removed it, just enough to get to the connector (referenced above) and plug it in.
I reinstalled the intake manifold and connected all the vacuum, pcv and fuel hose.
I go to start the car and it just cranks.

I disconnected and reconnected the battery, thinking it would reset any modules.
No changes.

Had the wife try to start the car while I wiggled the wire harness at the rear of the engine, thinking I loosened up some important wiring. No changes.

I removed and reinstalled the intake manifold again, thinking I maybe missed something. Nope, everything was connected.
Still cranks, but doesn't start.

Does anyone have any ideas? Is there something I am missing?

I'm not new the doing my own wrenching, but this has me stumped. Almost the the point that I'll have it towed to the dealer. This was a simple remove and replace of parts.

Fuel pressure is good. I know because each time I removed the fuel rail crossing the intake manifold, it was pressurized.

At no time did I remove the throttle body from the intake manifold and both the main harness and the map sensor are plugged in.

Thanks in advance.

 

Air leak betwix intake manifold and head? Are all the rubber seals in place and not flattened/hard(by heat/pressure)?

 

this is my next step, to be checked today.
im confident all seals are definitely in place. i would think this could cause a [significant] vacuum leak, but not something to prevent the car from starting.

since the intake manifold will be coming off again to verify this, ill triple check all other connections as well.

 

you may have a significant vacuum leak causing a no start.

If rear crossover pipe is replaced and manifold was removed, I would start there

MAFs, MAP and throttle body connector for the front, then the multi-pin connector for the manifold diverted valve/knock sensors, then the actual connector for the coolant pipe sensor. That is essentially all for that job unless something was stretched and damaged.

 

Appreciate the reply.
I removed the intake manifold again today in order to recheck the work.

Rear coolant pipe sensor is plugged in.

No loose wires, or wiggling of the harness at the rear of the engine made a difference.

the manifold diverter valve plug is the one at the bottom/back of the intake manifold? If yes, its plugged in.

Knock sensors are plugged in, connectors are snug.

intake manifold was reinstalled, taking time to make sure everything lined up and gaskets were in place

PVC hoses and vacuum hose crossing over intake manifold are connected.

Map sensor is connected.

throttle body harness is connected.

Maf sensors were never unplugged.

I checked the crank sensor to make sure it wasn't physically broken or disturbed. Wiring looks good.

I also checked fuses to make sure nothing for the ignition system was blown.


What is the multi-pin connector you speak of?

I have a feeling I may end up having it towed to the dealer. Luckily it's less than a mile from my house, but I'm afraid of the diagnostic fee. I have a feeling the fix will be easy, once they figure out what it is.

 

Posted below is a 5.0 intake manifold, green circle are the manifold seals(usually green). Check those for flatness, they have to be exposed from the manifold to seal against the head since they are rubber. The black circle is the area(passenger side) where there is a black or grey rectangular connector, it’s for the knock sensor harness and must be clipped in(make sure).

Without disassembly and if you think you have an air leak, spray ether around the intake manifold while someone cranks the engine, should pop or something at the least if you do.

 

unfortunately, still no progress.
The car cranks very strong, and has no hesitation cranking, but also no attempt to run. I cant help but think this is a electrical, spark, or sensor issue that is not providing a correct signal for starting. Its inability to even start/stumble/stall makes me feel it is not a mechanical problem.

yesterday when i removed the manifold (again), i made sure to take my time and inspect everything as I went along, those seals being one of the items. they were all in place, and seated properly.

I never disconnected the grey knock sensor harness plug. but i did move it out of the way. I will check again making sure no wires are broken on it.

I am going to stop by my local dealer today and ask them if I can have it towed there. hoping they don't take advantage since they are technically fixing a failed DIY repair. even though i don't think the current problem is related to coolant hose install, rather just a [electrical] casualty.

 

update...

stealership has determined that the plugs for the manifold diverter plug and the coolant temp sensor were swapped. $650 (after asking for a discount) to fix the problem. $190 diagnostic fee, $460 repair cost.

Im honestly surprised that those 2 connectors are interchangeable. oh well. expensive lesson learned. and hopefully some one in the future doing this repair finds this helpful.

 

I have the same issue. Im
just wondering which 2 connectors are the same. Can someone explains whatcha 2 they are?

 

I’m pretty sure the coolant temp sensor referenced is the one on the heater manifold pipe (a.k.a., rear crossover). The coolant temp sensor is on the passenger-side end of that pipe. I’m not sure exactly where the diverter is, but if they mixed up connectors, it must be right next to the coolant temp sensor somewhere.