So I've had an exhaust leak that I've been trying to pinpoint. Started off minor but has gotten worse over the last 1K miles. Thought it might be the DS manifold to Y pipe gasket but replaced that and no joy. Put muffler cement on the O2 sensor bung to hold things until Clay gets us headers made. Again, no joy. So I pulled the manifold and replaced those gaskets which made zero difference. Hmmm... Tested the coolant for combustion product contamination. Nada. Changed the spark plugs (and wires since I suffer from shipfitter's) which made me happy but did nothing for the leak. The video shows where I'm at now. Will the block/head be damaged from the leak? Won't know 'till I pull it I guess but I'm not optimistic by nature. Your thoughts?
exhaust leak(s)
- Thread starter Greg_M
- Start date
And it's way too cold to be faffin' about with this just now. Had to keep adding hot water to my soap mix to keep it liquid.
Do a leak-down test on the cylinders.. If they hold good pressure 'send it'! But she needs head gaskets, and Y pipe and O2.. Damn that's sad, modern quality today sucks.
But yeah, the exhaust leak is what lead me to finding bad head gaskets on mine. And banana heads.
But yeah, the exhaust leak is what lead me to finding bad head gaskets on mine. And banana heads.
My wife's Range Rover LWB blew the head gasket in front of number one cylinder. It blew to the outside, so no exhaust gas in the coolant or any other sign. It did sound like a Sopwith Camel in the end, spitting fire. And it did etch a groove in the cylinder head, a kind of flame cut.
I have a D1 project that a previous owner installed weld in generic catalytic converters. One of them has a big dent in it and I fully expect the internals have come loose from the body as I can tap on it with a rubber hammer and make it rattle. It sounds just like an exhaust leak until it warms up and then completely goes away. The sound comes from the area near this catalytic converter but I haven’t been able to determine the exact location of the leak. Maybe it isn’t a leak but instead noise from the converter itself. It has a rebuilt engine done by a previous owner and appears to have been run very little since. It is very clean. The engine is exceptionally quiet otherwise and has lots of power.. My suspicion is the rebuild was done by a good machine shop as the install of the engine itself definitely is sloppy compared to the quality of the engine assembly. I will be interested to know what you turn up.
EDIT - I am going to try your diagnostic method. Very clever approach!
EDIT - I am going to try your diagnostic method. Very clever approach!
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The good news is used 4.0 heads are plentiful and relatively cheap. Matt Gaum in Denver posted a couple dozen for sale on Facebook a while back for a very reasonable price. I found a brand new set a couple years ago on marketplace for $200. I bet Will Tillery has a good supply, too.
On my head leak I caught it fairly quickly ~200 miles. The head had a tiny amount of burning I could polish but the block was perfect.
Took 6 passes on the planer to get the heads flat again though.. PO had heads done before at LR dealership and when I got to it, I found some remains of the OEM gaskets still on the heads. Ie shitty work done at dealership.
Took 6 passes on the planer to get the heads flat again though.. PO had heads done before at LR dealership and when I got to it, I found some remains of the OEM gaskets still on the heads. Ie shitty work done at dealership.
If you do I'm curious if your O2 sensors leak. Mine are recently purchased from LRdirect.
I have seen O2 leak like that before, but not on my Rover. Normally they're the cheapest China "crimp wires" O2 that I've seen leak.. I went with Bosh O2 on my upstreams.. 1000 miles and still solid.
My Y pipe I got from Rock Auto. The first one I got had shitty welds and I sent it back for another one. 1000+ miles and not leaking yet.. knocks on wood..
My Y pipe I got from Rock Auto. The first one I got had shitty welds and I sent it back for another one. 1000+ miles and not leaking yet.. knocks on wood..
When I get a chance I'll dig out the O2 sensors I took out and see if they pass air. Good to know there's a better option (Bosch). Thanks for your input on both these parts.
I’d check them with a straight edge real well. If there in spec, may save you a trip to the machine shop. Mine were off so I went to machine shop to be shaved. I pulled the valves, cleaned them up, and put new seals in afterwards. Probably wouldn’t have hurt to lap them in but they looked great at the seats and valves so I didn’t. Truck runs great. I did use the ARP studs (rover ones not the shorter 215 ones). I also locktighted them in per ARP instructions (note optional). Just my two cents while ur at it. I also used Elring gaskets. Which are apparently good quality. It’s worth the effort to use quality parts especially if you’re going to keep it. Gordo
You're reading my mind Gordo. If I take it to a machine shop I'll do both heads. But I might just need a gasket. The heads have been done before so I'm tempted to do the driver's side only and skip the machine shop if it's flat. Two of the head bolts really(!) flexed my 1/2" breaker bar but my hernia barely noticed most of the others. Perhaps poor quality bolts or uneven torque are to blame in my case. This engine has 180 K miles on it so I've been thinking about finding a replacement to build for a future swap but stories of poor quality replacement parts concern me. It occurs to me that my fingers have thawed enough to type so happy days! Thanks for your input, I appreciate you taking the time to post. Cheers,
The sure fire way to find an exhaust leak is: Take a piece of brake line, like 12", and put a small bend 2" from the end. Then, attach a long piece of vacume line to the steel brake line. Put the end of the rubber line next to, but not in, your ear, and run the end of the brake line along the entire side of the engine and exhaust. You will hear the exhaust coming out of the rubber hose when you are next to it.
Much more experienced people than me say the rover V8 heads always need resurfacing when removed. But… the last set I had off were perfectly flat. I have another one that I took to a good machine shop that was 4 thousandth out and they told me to not have it resurfaced. I’d check it very carefully but flat is flat.
One of my D1s, it is clear only one head gasket was replaced by the previous owner. It runs just fine. I’d be inclined to fix it, doing the minimum now, and do as you are thinking, get one to rebuild for a future complete swap. But, I’d also really consider pulling both heads as a good amount of disassembly is already done. It would be a tough call more based on how happy I am with the condition of the engine otherwise, If you are planning to get a lot more miles out of it, I’d do both heads.
I buy my rover V8 rebuild parts from Turner in the UK. They build these engines frequently. If they use the parts I feel they are probably as safe a bet as you will find.
One of my D1s, it is clear only one head gasket was replaced by the previous owner. It runs just fine. I’d be inclined to fix it, doing the minimum now, and do as you are thinking, get one to rebuild for a future complete swap. But, I’d also really consider pulling both heads as a good amount of disassembly is already done. It would be a tough call more based on how happy I am with the condition of the engine otherwise, If you are planning to get a lot more miles out of it, I’d do both heads.
I buy my rover V8 rebuild parts from Turner in the UK. They build these engines frequently. If they use the parts I feel they are probably as safe a bet as you will find.