Vacuum Leak in 2010 LR4 V8

[gpanos2]

Anyone had an issue with an Engine Warning followed by normal operation of the LR4. I took the vehicle in and the Service Rep stated after applying the Engine Check Analyzer and the code read out the vehicle had a vacuum leak, which I took to mean either hoses or injection system, as the vehicle MPG went from consistent 18 to 13 while in operation before taking the vehicle to Land Rover for assistance. Anyone?

 

[scott schmerge]

Anyone had an issue with an Engine Warning followed by normal operation of the LR4. I took the vehicle in and the Service Rep stated after applying the Engine Check Analyzer and the code read out the vehicle had a vacuum leak, which I took to mean either hoses or injection system, as the vehicle MPG went from consistent 18 to 13 while in operation before taking the vehicle to Land Rover for assistance. Anyone?

did you check your pcv valves (on top of the passenger side valve cover). They are rubber valves and tend to develop a leak after about 100k mi. Spray some brake cleaner there and see if the engine stutters. If so, that’s your leak. Replacement is cheap, just make sure that you don’t break the valve cover plastic or you’re in for a much more expensive repair as you’ll have to replace the entire valve cover...ask me how I know.

 

[Ricardowelch]

Anyone had an issue with an Engine Warning followed by normal operation of the LR4. I took the vehicle in and the Service Rep stated after applying the Engine Check Analyzer and the code read out the vehicle had a vacuum leak, which I took to mean either hoses or injection system, as the vehicle MPG went from consistent 18 to 13 while in operation before taking the vehicle to Land Rover for assistance. Why your car is evaporative emission system leak, just visit AutoGuysLand for more info. Anyone?

Vacuum hoses can be dried out and cracked so that will cause vacuum leak.

 

[Kabooom2199]

Just happened to my 2010, right after I got it out of the shop. It is the two Positive Crankcase Ventilation disks on the valve cover. You can order them on Amazon for cheap. They work. Just have to replace them and drive the LR4 for about two hundred miles "drive cycle" and it will reset. The mechanic can't even reset the check engine light and keep it off....

 

[gpanos2]

Thanks all, very insightful and my research runs to your recommendations! Again, thanks!

 

[scott schmerge]

Just happened to my 2010, right after I got it out of the shop. It is the two Positive Crankcase Ventilation disks on the valve cover. You can order them on Amazon for cheap. They work. Just have to replace them and drive the LR4 for about two hundred miles "drive cycle" and it will reset. The mechanic can't even reset the check engine light and keep it off....

hmmm. I’d be skeptical of a mechanic that tells you this. CEL should and can be reset and codes should not reappear during initial drive cycle. Vacuum should be immediately restored and CEL should stay off.

It is true, if the computer is not reset, the CEL will turn off after it senses the vacuum is restored, however codes can be cleared immediately using testbook, gap iid, or the likes.

 

[Kabooom2199]

The mechanic did reset it. No engine light. Two miles down the road, light came back on and vehicle must go through drive cycle. Welcome to the wonderful world of emissions.

 

[DaytonaRS7]

The mechanic did reset it. No engine light. Two miles down the road, light came back on and vehicle must go through drive cycle. Welcome to the wonderful world of emissions.

Seems weird.
Clearing codes resets the ecu and its memory of emissions codes. The only reason the light would come back on so soon is if there is [still] a problem. Drive cycling only is necessary to set readiness and confirm the problem doesnt exist.

I've never had a car CEL come on after I've successfully repaired the problem and rest the ecu.

 

[scott schmerge]

The mechanic did reset it. No engine light. Two miles down the road, light came back on and vehicle must go through drive cycle. Welcome to the wonderful world of emissions.

As far as I know, if a cel comes back on it indicates a new code has been stored, not that an old code has to be “run through a drive cycle”. Did your mechanic tell you that the light came back because it needed to go through a drive cycle?

the only reason for a drive cycle is to check all systems are clear. So a computer cel will not come on unless it finds fault in one of the systems. (Which is why you can’t get an emissions inspection done until all cycles have been completed and the system reads ready).

If my mechanic told me this, I’d find a new mechanic. He’s either 1. Lying or 2. Doesn’t know what he’s talking about.