Exhaust Leak type noise only under load.
#21
06-14-2016, 06:25 PM
Hahah. Speaking of plastic....the Rover Gods attempted to curse me as I was swapping out my coolant in preperation for the trip.
I don't know how you guys get the coolant to drain nicely, I decided to use the bottom radiator hose. Bad idea. It was easy to get off (and then flush a few times with distilled water), but a PAIN to get the clamp tool on the clamp and clamp down.
As I was finally straining to put the clamp around the radiator nipple.......SNAP! The thin plastic suction hose that goes from the upper radiator along the radiator to the expansion tank snapped!
ARGH! The trip was the NEXT DAY. I was telling my wife to prep the Hummer H3 as it was looking no British engineering would be traversing the red-rocks that year.
But I searched some threads on here quickly and decided to buy myself about 50" of 1/4" fuel hose and routed that instead of the plastic. Sure, it's routed OVER the fan shroud (because you need more than 50", FYI) and zip tied in place, but it actually looks much tougher and it's most likely going to last much longer too.
So....yeah, plastic is HORRIBLE.
I don't know how you guys get the coolant to drain nicely, I decided to use the bottom radiator hose. Bad idea. It was easy to get off (and then flush a few times with distilled water), but a PAIN to get the clamp tool on the clamp and clamp down.
As I was finally straining to put the clamp around the radiator nipple.......SNAP! The thin plastic suction hose that goes from the upper radiator along the radiator to the expansion tank snapped!
ARGH! The trip was the NEXT DAY. I was telling my wife to prep the Hummer H3 as it was looking no British engineering would be traversing the red-rocks that year.
But I searched some threads on here quickly and decided to buy myself about 50" of 1/4" fuel hose and routed that instead of the plastic. Sure, it's routed OVER the fan shroud (because you need more than 50", FYI) and zip tied in place, but it actually looks much tougher and it's most likely going to last much longer too.
So....yeah, plastic is HORRIBLE.
The secret to the lower radiator hose is a regular band clamp. I have replaced all of the rover ones. Everywhere.
#22
07-17-2016, 03:23 PM
Got an odd one here. My engine "phtt phtt"s under load, sounds just like my old CJ7 V8. But if I"m under load down-hill or slip it into neutral and rev it, the old 4.0 sounds beautifully smooth with no noise at all..... (can an exhaust leak only be pronounced under load)?
It is a tapping sound, but does not sound like a pre-ignition or slipped liner.
It is a tapping sound, but does not sound like a pre-ignition or slipped liner.
But although others in this thread have reported the same thing I don't understand why it's evident only when the engine is under load. If there's a leaking gasket why wouldn't it be noisy all the time?
What's the hose check?
#23
07-18-2016, 09:05 AM
Winching
I think that the reason you do not hear it at idle is that there is little or no pressure pushing the exhaust gasses out from the engine down and thru the system. The engine is obviously working a lot harder up the hill, especially if you are not accelerating up the hill, just maintaining the speed you started at. I know mine really made "chugging" sounds if I did not speed up. I am sure that there is a far more technical response, but there is my $0.02
#24
07-19-2016, 12:39 PM
I think Matt is correct. Which is why I didn't think it was valvetrain even though it sounded like it. A stuck lifter is usually really bad at idle, but get some oil to it (load) and they tend to quiet down.
This was opposite: No noise at idle (because no backpressure) but horrible under load (gas blowing out the gasket).
The mechanic who found it for me (I was doing a routine safety inspection) said he just blew some canned smoke in the engine bay around the gaskets...at idle....and it was easy to spot.
You'll have to be fairly close to the gasket to make sure its the gasket and not just being blown by the fan. But there is still enough leaking at idle to blow smoke. Just not make noise.
This was opposite: No noise at idle (because no backpressure) but horrible under load (gas blowing out the gasket).
The mechanic who found it for me (I was doing a routine safety inspection) said he just blew some canned smoke in the engine bay around the gaskets...at idle....and it was easy to spot.
You'll have to be fairly close to the gasket to make sure its the gasket and not just being blown by the fan. But there is still enough leaking at idle to blow smoke. Just not make noise.
#26
07-19-2016, 07:41 PM
#28
07-20-2016, 08:44 PM
I tried the method shown in this YouTube video to confirm the diagnosis. Blew air into the tailpipe with my shop vac and then sprayed soapy water around the exhaust gaskets and looked for bubbles. Worked like a charm. Confirmed leaks at cylinder #2 exhaust gasket and at the passenger-side downpipe gasket. Pretty slick in my opinion. And no need to blow smoke.
The following users liked this post:
number9 (07-20-2016)
#29
07-20-2016, 09:34 PM
Thread
Thread Starter
Forum
Replies
Last Post
jcostello
General Tech Help
14
02-20-2007 07:18 PM