Is there still hope for my V10?

[JacobSyndeo]

Originally Posted by sibe

Seafoam works well BUT if you have onboard genny be CAREFUL in my RV 1996 .. the fuel line from tank to genny swelled and clogged .. ruined fuel pump and filter.. .. the lined used by winnebago was poor.. the OEM lines are OK.

I DOUBT is seafoam will fix compression.. normally valve deposits are oil leak down from valve stems etc.. yes the seats get cruddy but not enough to drop compression that bad..

I may hold off on it for now, then. I don't imagine they changed the fuel lines between 1996 and 2000.

Originally Posted by sibe

WHAT was the low reading of #3 in PSI.. was it like 120psi on all and 3 was 60psi or just 90... regardless , snakes in a can wont fix a burned valve or seat or wear from a bad valve guide..

PSI read between 20 PSI and 10 PSI depending on when it was tested. It's not just a "relatively low" thing like 90 or even 60, it's just low.

Originally Posted by sibe

Read the Chilton books, and watch videos all you can but the Trtion heads are a PIA, the Valvle cover needs to come up very high to clear the timing gear.. and manifold studs break etc.. It is a a tough DIY job...

Yeah… I'll read those books and see what videos I can find on it.

Originally Posted by sibe

Yes the cam followers can be an issue....read on them...but doubt it changed compression..

A low compression cylinder , not dead yet will still run well on a V10.. stumble, cause o2 reading off scale or imbalance ...

The mechanic saying the Cat is weak is noit worthy,, other than the o2 reading saying it could be, but fix the real issue and see what reading turn out to be, retest etc..

Yeah, it does seem to run well enough for me; I'm just wanting to avoid potential catastrophic failures that would be tied to that, not to mention the hit on MPG due to wasted fuel.

I imagine that sensors downstream detect all that and assume it's running way too rich, so it overcompensates for that by dialing back the fuel, and then it's running too lean. (But then why wouldn't I get a "too rich" code before—and in addition to—the "too lean" code?)

I also imagine a similar issue if I were to outright "disable" the cylinder by removing/disabling the injector (and spark plug too). I imagine that the sensors would detect less burned fuel in the exhaust gases than expected, and then try to compensate by adding more fuel, making them run rich.

But that's just speculation on my part. I really do wish there was a way to just forget about this one cylinder without any issues besides running at "only" 90% power. It's not like an I4 or I3 where I'd be down to 75% or 66%.

[CptBill]

Originally Posted by JacobSyndeo

I called the place I had it checked out at, asking for more specifics on why they're refusing a repair, and they said that repairing the valve in question would make "too much compression" compared to the lower compression level the engine is now "used to", which could "blow out the bottom end". They said it in a way that almost sounds convincing, but I'm not sure how much I buy it, TBH.

That is a crap statement. If your not mechanically inclined find someone who is and first have them check the exhaust manifolds, plugs & coils then go from there

[Unplanned Tourist]

If you only have 10 - 20 psi on the low cylinder, the valve must be in bad shape. I would be leary of running it too much more in case it drops the head off of the valve. Then you definitely will need a remanufactured engine.

[JacobSyndeo]

Originally Posted by CptBill

That is a crap statement. If your not mechanically inclined find someone who is and first have them check the exhaust manifolds, plugs & coils then go from there

Interesting. I'll check them out when I get the chance, probably this weekend. I generally know what I'm looking for with coils and plugs, but I haven't worked with exhaust manifolds yet.

Originally Posted by Unplanned Tourist

If you only have 10 - 20 psi on the low cylinder, the valve must be in bad shape. I would be leary of running it too much more in case it drops the head off of the valve. Then you definitely will need a remanufactured engine.

If what you're describing is what's shown in

this video

, then that's a big yikes.

The seller's mechanic did say that cylinder 3's valves are the culprit, as far as he could tell.

Circling back to what CptBill said, if that statement really is crap, then I primarily need someone to just work on the valves. Engines are not my field of expertise, but from what I understand about engines, I'm pretty sure it could either be a damaged (or at least very dirty) valve that's not sealing properly, or something about the cam or the lobe that is causing the valve to be open too long. Does that sound about right?

[Russ Silber]

A good mechanic should have a borascope (hope I spelled it right) to see from the spark plug hole if valve is bad. Some one can rotate crank to observe it action. Did that with aircraft engines.

[Unplanned Tourist]

An old mechanic trick is to put about 2 tablespoons of oil into the spark plug hole and repeat the compression test. If it goes up, likely bad rings. If no or little change, bad valve.

[CptBill]

If indeed you have low compression on one cylinder the the thing to do is pull the head before condemning a good engine with a little problem

[JacobSyndeo]

Originally Posted by Russ Silber

A good mechanic should have a borascope (hope I spelled it right) to see from the spark plug hole if valve is bad. Some one can rotate crank to observe it action. Did that with aircraft engines.

Borescope; I actually do own one. Used it to check the valves on my car's GDI engine; those are notorious for buildup due to the lack of gasoline detergents being injected upstream.

Originally Posted by Unplanned Tourist

An old mechanic trick is to put about 2 tablespoons of oil into the spark plug hole and repeat the compression test. If it goes up, likely bad rings. If no or little change, bad valve.

Worth a shot to find out for sure, before doing the more complicated valve stuff. I imagine the mechanics already tried this, but I'll try it just in case they didn't.

Originally Posted by CptBill

If indeed you have low compression on one cylinder the the thing to do is pull the head before condemning a good engine with a little problem

My thoughts exactly—it seems like a good engine overall, and such a waste to throw it all out.

[edge68474]

This is a great post and answers from the forum.
Both my pickup and MH have Triton engines.
I agree with using ONLY Motorcraft plugs and coils.
Tried using a different brand of plug some time back on the pickup, NO GO.
Went back to Motrocraft, no problems. And if I were you, I would change both plugs and coils. I have Ford put in new plugs because of the plug problems in the past, and I put in the coils, real easy. I think they have changed plugs now but I still don't do them. After about 80,000 miles on plugs and coils, I start thinking of replacing them. They'd probably go to 100,000 miles, but I think that's pushing it, and in a MH on the road, why chance it.
I am going to follow this post, thank you.

[computerguy]

Originally Posted by JacobSyndeo

A rebuild has us looking at at least a 6-month wait and about $23K, according to a quote from this particular shop. That's not only over 3x what we paid for this RV, but more than what this RV normally sells for ($15-$20K range).
...

I know a "little" about getting a V10 replaced recently. Feel free to read my nightmare. But everyone still says this engine is the best thing since sliced bread. But like any IC engine there are problems. Lots of them. Simply do some searches.
but I am not hear to argue.
$17k I paid last month. That included a new intake manifold and new power steering pump (both Ford, new).
Sounds like your shop may be overcharging or not sure of the work.
Yeah, that wait is real. I only was able to get action from Ford because they were on notice for paying my expenses after the first engine they sent was also defective. I contacted a number of C suite executives and got action to get it earlier.
Best of luck in your project. Only you can decide on if it is worth it.
My nightmare thread https://www.irv2.com/forums/f23/2015...ts-580969.html

[sibe]

Originally Posted by computerguy

I know a "little" about getting a V10 replaced recently. Feel free to read my nightmare. But everyone still says this engine is the best thing since sliced bread. But like any IC engine there are problems. Lots of them. Simply do some searches.
but I am not hear to argue.
$17k I paid last month. That included a new intake manifold and new power steering pump (both Ford, new).
Sounds like your shop may be overcharging or not sure of the work.
Yeah, that wait is real. I only was able to get action from Ford because they were on notice for paying my expenses after the first engine they sent was also defective. I contacted a number of C suite executives and got action to get it earlier.
Best of luck in your project. Only you can decide on if it is worth it.
My nightmare thread https://www.irv2.com/forums/f23/2015...ts-580969.html

This poor guy went thru hell and back on a motor job, it was a poop happens moment twice,, a premature valave drop, ( common on V10) and then a replacement engine with a faulty head.. Bless you sir..

BACK to the OP and his issue,

1. Confirmed that #3 Cylinder is low on compression , About dead with 10-20psi...

SO DO NOthrow money or resources on New plugs, coils or a fuel additives etc...

Need to find out more on the #3 cylinder, a mechanic with bore scope can help detect a bad valve probably if he know his STUFF.. IF the valve lookc ok, is there a lifter noise or worn rocker/follower not actuating the valve.. that is rare but pulling the valve cover may be in order BUT that is a PIA on these motors..couple hours normally to R&I..

I am only trying to guide a bit logical here.. I am very adept on DIY stuff being in the Auto repair/mechanics, now Collision repair as a apprentice starting in 1976, owning my shop since 1984..

If it was my beast, I would do the job of 2 reconditioned heads or updates and roll the dice that the bottom ends is solid,, but I would take into account any service records and general visual condition of the RV/motor..

I have told my story many many times.. of a well cared for 137K RV I bought that is still going strong with the 3rd owner noew just returning from a MOAB trip back to PA,, 216K on it and running well..he messaged me last nite, it hasn't miised a beat, he changed the oil out there for the trip back.. asked be if he should ,, I said YES,it was almost 3400miles on oil.. He drive foot to floor loaded..LOL
Then my recent 96 bought with only 28K.. runs great but had gremlins.. LOL