Camshaft - how bad?

[robbyb20]

Welp, time for some maintenance. This time its the valve train/lifters/pushrods/.camshaft.

I have everything out except the camshaft which I was hoping i wouldnt have to given the extra stuff I have to pull off in front.

Here is a photo of the current camshaft, i have a new one on hand. Is this thing totally f-ed? The color youre seeing on it is NOT oil. The lobes *look* ok but seeing the top coating worn off is concerning.

This is my first time doing this so please give me some slack on if this looks obviously totally fucked and I should just know! hah

 

[kris812]

My 2 cents is that cam looks burnt (ran with oil without Zinc) and should be replaced while in that deep.

Whenever I did my heads I looked over the Cam really well, but now I'm wishing now I would have gotten a micrometer on it to measure lobs.

Well I think cam and lifters should be changed. At 140k when I did my heads the cam looked great compared to this!

How many miles? What oil did you run?

 

[robbyb20]

My 2 cents is that cam looks burnt (ran with oil without Zinc) and should be replaced while in that deep.

Whenever I did my heads I looked over the Cam really well, but now I'm wishing now I would have gotten a micrometer on it to measure lobs.

Well I think cam and lifters should be changed. At 140k when I did my heads the cam looked great compared to this!

How many miles? What oil did you run?

Thanks for the insight. It has about 193k miles on it. Not sure about previous owner, ive been running Rotella 15w40. I havent consistently been putting in extra zinc/zddp.

I guess my next question would be if i need to worry about the cam bearings. I have a spare set on hand just in case. Guess i would find out when I pull the cam and see what those look like.

 

[kris812]

Btw, it looks like a score mark on the 3rd down from top. And possibly some chips in the lower 2. The only lob I can see is the bottom most. It looks sharp enough aka has a lobe.

Honestly at 193k it's probably due for a cam. At 140 I was really on the edge. You could micrometer the lift on lobs and know for sure what she's got left in her.

It could very well be all the additives, but I doubt it. As for cam bearings, idk man, once you do that might as well pull for full rebuild. Not much of a motor left to pull out, you know? If the old and new cam doesn't shake in there, send it!?

 

[LRDONE]

Thanks for the insight. It has about 193k miles on it. Not sure about previous owner, ive been running Rotella 15w40. I havent consistently been putting in extra zinc/zddp.

I guess my next question would be if i need to worry about the cam bearings. I have a spare set on hand just in case. Guess i would find out when I pull the cam and see what those look like.

What do the lifters look like? That will tell you everything. My truck was falling on it's face at high rpm, I had a few lobes that were rounded. I have pictures on this topic somewhere in here.

FWIW, too much zinc can hurt things, high detergent diesel oil can wash the components of zinc and other additives. I recommend with a new cam and lifters, you should run the proper weight and use a oil with zinc formulated into the oil, not additive.

 

[robbyb20]

What do the lifters look like? That will tell you everything. My truck was falling on it's face at high rpm, I had a few lobes that were rounded. I have pictures on this topic somewhere in here.

FWIW, too much zinc can hurt things, high detergent diesel oil can wash the components of zinc and other additives. I recommend with a new cam and lifters, you should run the proper weight and use a oil with zinc formulated into the oil, not additive.

Lifters for the most part look ok but there are a handful that have a very VERY tiny amount of pitting. Almost unnoticeable until you look at it in sunlight. Replacing those are happening either way.

So Ive been using Rotalla T4 15w40 but for the break-in, I suspect ill need to use something without detergents. i can assembly lube to reassemble, any suggestions on regular oil to run (other than above) or break-in oil?

 

[robbyb20]

Btw, it looks like a score mark on the 3rd down from top. And possibly some chips in the lower 2. The only lob I can see is the bottom most. It looks sharp enough aka has a lobe.

Honestly at 193k it's probably due for a cam. At 140 I was really on the edge. You could micrometer the lift on lobs and know for sure what she's got left in her.

It could very well be all the additives, but I doubt it. As for cam bearings, idk man, once you do that might as well pull for full rebuild. Not much of a motor left to pull out, you know? If the old and new cam doesn't shake in there, send it!?

I think it only makes sense to just pull it out while im in here. Ill be able to see more once I get it out. I didnt feel any putting on that one you mentioned but who knows. Ill pull it in the next hour.

Im assuming ill have to take the radiator out. Anything else to get in the old cam out/new cam in?

 

[terryjm1]

I wouldn’t put it back together without a new cam. Rover V8s are hard on camshafts.

 

[robbyb20]

Cant get the camshaft out without removing the condenser. First time having to do that.

ANy tips on removing? I do not have a way to recapture the refrigerant. Will that matter a ton?

 

[kris812]

Cant get the camshaft out without removing the condenser. First time having to do that.

ANy tips on removing? I do not have a way to recapture the refrigerant. Will that matter a ton?

You can rent a vacuum pump and gauges from AutoZone for free. Takes about 3 cans to fill the AC, I've been getting from Walmart for 10$ a can chasing a leak. (Shrader valves were leaking at 120+F ambient temps).

Replace those condenser o rings along with o rings on Rad cooler lines. The AC dryer is behind the front grill if you wanna change that before doing the AC vacuuming / filling.

 

[boxster]

Cant get the camshaft out without removing the condenser. First time having to do that.

ANy tips on removing? I do not have a way to recapture the refrigerant. Will that matter a ton?

PT Schram, attests he won’t remove condenser when R&R cam shaft he swings it up and out of the way hanging with a bungee cord. I believe he has a post on this job somewhere in the forum posts.

 

[kris812]

Personally, 30$ in r134a and free tools from AutoZone to recharge the AC; I'd never risk damaging the condenser nor the new camshaft install over 30$ in gas. Not even sure a new condenser can be purchased.

Easy job and cheap to recharge. But my 2 cents, at least change the 2x r134 shrador / AC fill valves while it's discharged. Universal AC fill valves on USD D1s so Stems are cheap.

 

[terryjm1]

Personally, 30$ in r134a and free tools from AutoZone to recharge the AC; I'd never risk damaging the condenser nor the new camshaft install over 30$ in gas. Not even sure a new condenser can be purchased.

Easy job and cheap to recharge. But my 2 cents, at least change the 2x r134 shrador / AC fill valves while it's discharged. Universal AC fill valves on USD D1s so Stems are cheap.

When I replaced my compressor I replaced the drier and all the o-rings in the system. Wish I would have thought to change the shrader valves. But, knock on wood, 4-5 years later it still cools very well, as good as my new Toyota It cools so well it cycles on and off a lot even in the high 90s. Agree, if you open it up, change every o-ring and easily serviced part you can. Also, the compressor is really easy to take apart and change the seals. In my research the compressor seals are the most common leak. It is a very common base compressor and very durable. It is used on many different types of vehicles. The differences mainly are the manifolds and clutches. Before I realized how easy it is the replace the seals I purchased a brand new one listed for a BMW on eBay for something around $100. I also replaced the hoses. I sent them off to an AC place and they reused the fittings. Aside from the hoses, all the service items were pretty inexpensive. The compressor seal kit was less than $20. The hoses were not too costly. It was pre Covid but they were $50 each. I have since purchased a kit to redo hoses myself. i haven’t used it yet as I haven’t needed to. For all the complaining. I hear about D1 AC, I have been pretty happy with mine. Two of mine, from what I can tell, are all original and still work well.

 

[kris812]

FYI, they make a tool to change the AC shrader valves while the system is charged and is how I changed mine. Just think of a spacedock, put on tool, unscrew and move valve to a different chamber to remove and replace. Pretty slick stuff, I've seen it done on home HVAC so knew that tool existed.

But yeah new compressors should always get a new dryer. Heck probably even an opened system for more than an hour disserves a new dryer.

But a major question here! Your AC compressor cycles?? Do you have rear AC? In 20 years of working AC and 2 compressors I've never seen my compressor cycle on this truck! As I understand there are 3 expansion valves on the 3 evaporator cores. In that case the compressor should run constantly and the expansion valves control flows.

idk maybe I've always had something wrong, or it really is that hot in AZ it never cycles lol jk.

 

[terryjm1]

On the cycling, I should have explained more. When I replaced the V8 with the TDI I foolishly sold the engine with the full wiring harness attached. I didn’t think I would need it. As such, I didn’t have the rather necessary wiring for the AC. So, I created my own control system using the factory switches / sensors. I wasn’t 100% sure it would work but it stays very cold even with regular cycling. With the V8s with factory set up I haven’t really paid attention. The engine doesn’t bog down like the TDI when I turn it on. I just assumed it also cycled.

 

[kris812]

On the cycling, I should have explained more. When I replaced the V8 with the TDI I foolishly sold the engine with the full wiring harness attached. I didn’t think I would need it. As such, I didn’t have the rather necessary wiring for the AC. So, I created my own control system using the factory switches / sensors. I wasn’t 100% sure it would work but it stays very cold even with regular cycling. With the V8s with factory set up I haven’t really paid attention. The engine doesn’t bog down like the TDI when I turn it on. I just assumed it also cycled.

Might also explain why you're getting SO much better gas milage than me at 10-11mpg city! Maybe without rear AC the system cycles from the factory IDK. But cleaver you got it working and cycling like other vehicles do!

What is the off trigger, the high pressure switch?? I think that is around 450psi.. If so, wowza it holds that!
(I charged up to 345psi on a 110f ambient day)

But if it isn't broken, DONT FIX IT!!

 

[robbyb20]

Thanks for the help guys. New cam is in, it was a little touch and go in the first 10 seconds after start up during the break-in process but then smoothed out. Might pull apart the top end to inspect in a month to see if theres anything wrong but other wise ill just keep driving.

I got the old one out, it was much more apparent there was a lot more wear. If i have to do this again, it wont feel so daunting.

 

[discostew]

Cant get the camshaft out without removing the condenser. First time having to do that.

ANy tips on removing? I do not have a way to recapture the refrigerant. Will that matter a ton?

I think you can get it off its mounts and with it still attached to the lines tilt it up high enough to clear the camshaft coming out the front.

 

[terryjm1]

“What is the off trigger, the high pressure switch??”

When I get bored I will hook up the gauges and note the pressure it cuts out. I cant remember from when I did the work. But yes, that was the assumption when I planned it out.

There is also an icing sensor at the evaporator that can shut it off. I made sure to keep that in the loop. It’s so dry here I doubt that it ever activates, however. .

When I did the job I realized there are multiple relays interdependent on each other with multiple input factors that control the AC operation, some of which went away with the factory wiring harness and EFI. I just greatly simplified it to one relay for the AC and one for the condenser fans. The only part that was a bit unique was a one way diode to separate the condenser fan circuit from back feeding when the fans come on due to temperature. My “guide” was the operation of my old 1980 Triumph TR8 system, which also gets really cold. I just copied it for the most part. I cant recall but don’t think the TR8 has an icing sensor, though.

There is a downside to all of it. The defroster doesn’t utilize the AC unless I push the AC button. I’m ok with that. If the air and heat alone don’t clear things up I just push the AC button. So far, the air movement and heat does the job just fine. It’s almost never very humid here. I guess there is one other downside, the idle speed doesn’t bump up when the AC goes on. But, it drops less than 50 rpm, probably 25 to 30 but I can’t specifically say as the tachometer is what it is in these trucks. It makes it easy for me to notice it cycling as well.

Also, I didn’t investigate how a D1 originally equipped with a 300tdi controls the AC operation. I’m going to bet it is pretty similar to what I have done.

I was in the desert yesterday in 90 plus temperatures and was nice and cool.

I don’t plan to sell any of my LRs but I definitely won’t sell this one. I have done too much “undocumented reworking” to hand off to someone else. It would drive anyone else completely mad trying to diagnose if something stopped working.

I don’t plan to make changes to my V8 D1s. The changes on the 300tdi were out of necessity.

 

[kris812]

Do NOT check your pressures, let's just assume and not break something working!

But I'm going to guess here in hotter ambient temps it doesn't work as well as the pressures will be higher, thus turning the compressor off sooner, less dV across the evaporator, warmer air.

But this is theory's here. It's possible I am undercharged, never cycling and not getting full cooling.. Filling AC per Rave and LR is per weight of r134, not pressures. I haven't weighed in, I just filled up per r134 charts.

To note, idle speed is 950 with or without AC. Little bog whenever first turned on.

You could use the defroster relay to trigger the AC relay like the factory, but I see NO problem in the way it's wired!

And the fact it's YOUR Rover forever, the more mods the better!