Water pump replaced, still leaking coolant

[Mozambique]

Agree with the fix issue plus PM approach.
The crossover pipe seals looked flattened, think it was leaking from there as coolant in the valley between the two banks towards the front end.
Also replaced rear heater manifold (same crappy plastic), and the flexible hose that runs under the intake manifold. Looked fine, but sensible to replace too.
Water pump done (not sure if leaking from there) and the rigid plastic pipe out of the back of the water pump (garage originally diagnosed the seal on this was causing the leak).
Just road tested it this morning and coolant levels seem fine. Certainly no leak down the front onto the vacuum pump as was the original problem prior to the work being done.

CEL showing some manifold pressure fault codes. Was not doing that prior to my changing the crossover pipe etc. I noticed a tear in the 6" long rubber hose which connects to a rigid pipe leading to back of engine on RHS (as you look at it). The rubber hose connects to the 'air box' (the twin-box thingy which connects to the front of the throttle body). I temporarily taped the tear until I can get a replacement hose. Cleared codes........ fingers crossed

 

[jlglr4]

That tube you fixed sounds like the crankcase breather. A tear in that hose would give you a lean condition I believe.

Not sure if you have a MAP sensor on the V8, but on the V6, the MAP sensor is on the back of the intake manifold and is very easy to forget when putting everything back together (because you can’t see it at all). If you have a MAP sensor on the V8 and it’s not plugged in (or not plugged in completely), that would definitely give you a manifold pressure error.

 

[bgbrown125]

2010 LR4 V8 with 90k miles.
So I had a v slow coolant leak for 6 months that started getting faster. Took it to my regular garage and they diagnosed the plastic pipe off the water pump was leaking. I got them to replace it and also the water pump as PM. got the car back and still leaking at same rate with coolant visible as per pics. Level in reservoir dropping by a couple of inches every 100 miles or so.
took it back to garage, However after the 30 mile drive to the garage there was no visible leakage?? they did a pressure test for a couple of hours and still no leakage. I questioned their original diagnosis and asked them if maybe plastic crossover pipes could be the problem. Could be leaking from more than one place? Was told they tend to fail catastrophically as opposed to slow leak.
I took the manifold at the front off, the one which connects to both air filters to get a better view, source of leak not clear.
Before I take it back to them again, I thought I would ask here?
Already spent $CAD 1k on water pump and pipe replacement so far.......not leaving me feeling warm and fuzzy.
Any help much appreciated!!

I have a 2000 Disco II with V8. I had a leak that no one could diagnose and it turned out to be leaking through a bolt hole in the timing cover. Replaced all of the gaskets assocoated with the timing cover and it has never leaked since.

 

[Mozambique]

Yes there is a MAP sensor. I believe I plugged it back in. If code returns will double check its connected properly.
Was having MAF codes before coolant leak. Initially came on then disappeared on its own a day later. Went on like this for a couple of months before becoming more persistent. Cleaned both MAF with correct solvent. Still issue. Replaced one. Still issue. Switched new one to other side. Then car off road getting coolant leak fixed.
Along with MAF codes was getting P0106 MAP code. Maybe MAP was going bad too?
Am also now getting P2135 throttle body position sensor error. Seems unrelated to any of above? Random coincidence?
Aren't CEL's fun????

 

[jlglr4]

Lot’s of fun. The MAF, MAP, and throttle body are all related, so if one is messed up, I think it can trigger problems in the others. Basically, engine expects certain mainfold pressure (MAP) at a given throttle position (TPS) and airflow (MAF). Further complicating it, I believe the throttle position is double checked against the accelerator pedal position sensor. I have seen reports of the P0106 resulting from a dirty throttle body, and I’m remembering the oily film build-up on your butterfly valve. Maybe it needs a cleaning - maybe clean the MAP too if it looks sooty. Otherwise, perhaps some chafing on the wiring harness.

 

[Mozambique]

Hhhhmmm....... did clean the inside of the throttle body. Its funny though, only P0106 manifold absolute before I fixed the coolant leak. Now P0069, P0208 and P0106 all manifold pressure related, plus the TPS error code. Codes triggered as soon as I started the car. Will double check MAP sensor connections tomorrow. Then off for 400km return trip. Engine running fine, so fingers crossed. No MAF specific codes at least. Will try cleaning MAP too as you suggest. Thanks!!!!
While I had the intake manifold off a 1/4 cup of oil drained out of it. Bit alarming.

 

[Mozambique]

Success!
I had only partially reconnected the MAP sensor plug. Clicked it on whole way and CEL gone.... hopefully not to reappear

 

[jlglr4]

That’s great news. Thanks for posting back. Hope that’s the end of it.

 

[Balto]

Looks like you got it all fixed but just wanted to say that I had a coolant at about 50k and went ahead and had the water pump and front+back pipes replaced…….discovered the next day that I still had a leak….took it back and it ended up being the Thermosta! Sprayed everywhere but once fixed leak was gone and she actually ran better.

just wanted to throw that your way in case leak comes back.

 

[Mozambique]

When the garage did the water pump I questioned whether to do thermostat too. They said don't bother. Will bear in mind if leak returns