Is there still hope for my V10?

[JacobSyndeo]

Hi all,

I have a 2000 Fleetwood Southwind motorhome built on Ford’s 1999 F53 platform, running a 6.8L Triton V10 with 110K miles. I got the whole motorhome for $7K last month (this model goes for $15-$20K these days), knowing in advance there were engine issues related to low compression, and aware that work needed to be done. The seller’s mechanic said a valve issue on cylinder 3 was to blame, and that a basic valve job should resolve the issue.

It seems to drive just fine, no issues I can notice, but the Service Engine Soon light is lit. No blinking yet, but still, not optimal.

It’s hard for me to tell if there’s a loss of power, as I haven’t driven anything quite this large or heavy before, nor am I mashing the gas pedal (considering the CEL is on, and considering the current price of gas), nor have I driven it before it had the issue.

My OBD-II tool displays a nice handful of codes:

Primary code:
P0300: Random Misfire Detected

Stored codes:
P1406: Differential Pressure Feedback Sensor Downstream Hose Off Or Plugged

Pending Codes:
P0303: Cylinder 3 Misfire Detected
P1131: Lack Of HO2S11 Switches - Sensor Indicates Lean
P1151: Lack Of HO2S21 Switches - Sensor Indicates Lean
P0155: "O2 Heater Circuit (Bank 2, Sensor 1)"
P0171: System Too Lean Bank 1
P0174: System Too Lean Bank 2

Now, I’m no engine expert (so correct me if I’m wrong), but it seems that these are the issues here:

1. Low compression in Cyl 3, ostensibly caused by a valve issue, leading to misfires
2. O₂ sensor issues, likely just needs new sensor(s)
3. Running too lean, possibly due to issue 2
4. Diff pressure feedback sensor either needs a new hose, or its hose is disconnected

From what I understand, the O₂ sensor is a big part of how the ECU knows what air/fuel ratio to use, so perhaps issue 3 is a consequence of a bad O₂ sensor and/or heater.

I’m not familiar with issue 4’s sensor, but I do have what appears to be a small hose loose in the engine compartment; maybe it’s related: https://www.ford-trucks.com/forums/1...connector.html

The reason I’m making this post right now is that there’s really only one shop in my area that works on motorhomes… and they know it. This is my first time working with them, and they were quite rude to me when I was dropping it off for them to inspect (stifling laughter at me when I said it was misfiring), so they just gave off a really sleazy vibe, and I don’t trust them.

They want to replace the entire engine, and charge me upwards of $20K (incl. parts and labor) to do so.

I really don’t think that’s necessary (I’ve got 9 perfectly-functional cylinders!) but I wanted to run this by some knowledgeable folks who have nothing to gain monetarily here one way or another. The seller’s mechanic says likewise, but doesn’t have availability to work on it anytime soon.

Does this sound like something that could largely be resolved by a valve job, some new O₂ sensors, and a new hose?

Thank you for reading, and for your time. I’m looking forward to hearing your thoughts!

[2cyber71]

Get a rebuilt engine.

[l1v3fr33ord1]

JacobSyndeo-

Welcome to iRV2!

Re: The V10. I would not give up on it. I suggest you find a trustworthy car mechanic or a mobile Ford repair person. I used both to repair and maintain my coaches (now sold). I would avoid RV repair shops. If you have a mechanic whom you trust, start with him. Local Ford dealers or RV parks can recommend honest mobile chassis repair people. I once had a mobile RV repair fellow say "I only work on the house portion, but I know a guy who works on the Ford chassis out of his truck." He gave me the contact info and it turned out to be a great (repair) experience. So don't hesitate to ask for other recommendations as you move along.

Here is a link to post on a Web site run by a former iRV2 member, dedicated to his 1999 Southwind. You'll notice on his site that he had done a lot of work on his coach's V10 engine. There's lots of great info for you on that site.

By the way, loose or broken exhaust manifold studs are common on the 2000-era V10 engines. Those causes will affect the proper operation of the engine, especially related to the exhaust fuel-air sensors.

Finally, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

[SergioP]

Find a shop that knows V-10’s. Then find out why the misfires. These engines are used in a bunch of Ford trucks. There’s a shop in Ohio that rebuilds these engines in his shop. He farms out the machine work but he disassembles, assembles and installs the engines.

A rebuilt Ford engine installed is probably $15k. Maybe you can get by with a new head or valve job.

[baraff]

Have the spark plugs ever been changed?
Our 2005 V10 states plug change at 100K miles. I changed them out at 90,000.
Also, coil packs.
Get OEM Motorcraft plugs and coil packs, don't trust the cheap chinese stuff.

And you need to find an honest shop.

[JacobSyndeo]

Originally Posted by 2cyber71

Get a rebuilt engine.

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).

So I'm hoping things aren't really at that point yet.

Originally Posted by l1v3fr33ord1

JacobSyndeo-

I would not give up on it. I suggest you find a trustworthy car mechanic or a mobile Ford repair person. I used both to repair and maintain my coaches (now sold). I would avoid RV repair shops. If you have a mechanic whom you trust, start with him. Local Ford dealers or RV parks can recommend honest mobile chassis repair people. I once had a mobile RV repair fellow say "I only work on the house portion, but I know a guy who works on the Ford chassis out of his truck." He gave me the contact info and it turned out to be a great (repair) experience. So don't hesitate to ask for other recommendations as you move along.

Here is a link to post on a Web site run by a former iRV2 member, dedicated to his 1999 Southwind. You'll notice on his site that he had done a lot of work on his coach's V10 engine. There's lots of great info for you on that site.

By the way, loose or broken exhaust manifold studs are common on the 2000-era V10 engines. Those causes will affect the proper operation of the engine, especially related to the exhaust fuel-air sensors.

Finally, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

Thank you; I really do want to stick it out with this one, if only because rebuilds and crates are prohibitively expensive.

I live in the Boise area, and unfortunately there's not quite as many mechanics out here as in the more populated states. I had to call about 20 or so shops before I found even one that would even take a look at a motorhome…*and their lot was chock-full of other motorhomes, presumably since the local market is starved for competition.

But you're suggesting a mobile mechanic, huh? I'll look into that!

And that website looks like a fantastic resource; I'll definitely be bookmarking it.

Originally Posted by SergioP

Find a shop that knows V-10’s. Then find out why the misfires. These engines are used in a bunch of Ford trucks. There’s a shop in Ohio that rebuilds these engines in his shop. He farms out the machine work but he disassembles, assembles and installs the engines.

A rebuilt Ford engine installed is probably $15k. Maybe you can get by with a new head or valve job.

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.

Due to the pricing alone, I'm definitely leaning towards getting the valve fixed first. Just need to find someone else willing to work on motorhome engines now… perhaps a mobile mechanic like l1v3fr33ord1 mentioned will be up for it.

Originally Posted by baraff

Have the spark plugs ever been changed?
Our 2005 V10 states plug change at 100K miles. I changed them out at 90,000.
Also, coil packs.
Get OEM Motorcraft plugs and coil packs, don't trust the cheap chinese stuff.

And you need to find an honest shop.

Not sure if they've ever been changed… that's been on my radar ever since I read about an issue that causes the plugs to actually shoot out!

While replacing the plugs is something that should definitely be done, I'm not positive the compression issue would be fixed by doing so.

[sibe]

tough cll on this one, 110K on motor.. Those motors are a PIA to try and take off the heads in place,, I have done the baby 5.4 in pick up.. lots of time and sore back..
As said a rebuilt is best,, expect 5K-7500 or adecent rebuld and then some add on stuff.. manifolds, sensors, waterpump, tune up items.. etc..

Labor will be a premium as a MH is a specialty vehicle and the sky is the limit on $$$..

you can easily dump 8000-15K into the job, depends on the rebuild, the shop doing the job.. prices are all over the place...

As far as the issues you have... the misfire on 3,, verify compression that tells the story.. Valve issue is known possible thing on a v10.. leaky manifolds dont help valves.. they can attribute to the o2 codes and lean readint but,, the low compression is major issue,

[sibe]

The statement that fixing the head and compression will cause motor issues, is not true BUT New/recon heads will provide good running and the next weakest link may break.. at 110K, it is a toss up, not knowing the care and how hard it was used,,

I texted a buddy, 25 year ford dealer mechanic, has his own shop now.. does more diesels but does a limmo bus companies work..

Heads, expect 900-1500 for a RECON set.. DO not DO one, DO both..

Timing kit. followers etc,, Gakets, Bolts kits, Manifolds, or cut/tru your old ones... Tune up parts, Fluids etc,, figure 600-1100 depends..suggests injecters also..

Labor Min 14 hrs PLUS..atleast 4-8 in misc.. Approx $1800-2500..

You can easily be at 5k to do 2 heads. ,/fix exhaust leaks, sensors etc..

, In vans he pulls them.. so a motorhome?? he said depends.. would not guess a price..

I would chance 2 recon headsm manifolds and associated parts to get it running,, dumping 5k into it still gives you a savings and a good motor all tuned and ready to go ....


Good luck on the quest..

[donr103]

Slide under her.. and check exhaust.. see if po removed cats.. see if the sensors are even there.. po may have taken off e gr valve or disconnected it.. that is where I would start.. next.. grab a book on Ford v10 engine.. and basic automotive repair book for 2000 Ford excursions.. with v10.. same eng and trans.. I like Haynes and Chilton.. after reading.. do basic tune up.. even if you put new engine in.. you will need these parts..
Do the engine yourself.. save 15,000.00 get 2000 era v10 out of salvage yards.. look at visione rv salvage yards in ky . There are probably closer salvage yards near you.. they only need basic tools to pull one..
Good luck and keep us posted

[l1v3fr33ord1]

I note that the OP's first post implies he was told there was a valve/compression problem on cylinder #3, but nothing in that post says to me that the OP has had someone confirm there's a valve/compression problem. I think that on these V10s a misfire can result from a failing coil pack (as "baraff" mentioned), probably more often than a valve problem. I could be incorrect about this, though.

Another sign that makes me wonder is the OP doesn't report any obvious stumbling or power-loss symptoms.

A low-cost, low-effort, no compression-tool approach would be to install a new Ford OEM coil pack on cylinder #3, test for codes, then clean the MAF sensors, test for codes, then possibly replace one or both O2 sensors, test for codes. I can't imagine being in for more than $500 by that approach.

Still, better to find an honest and trained mechanic. Mine works on my cars, and wasn't afraid to work on the motorhome when I suggested he do so. It didn't fit in his shop, so we had to wait for sunny, dry and reasonably warm days- but it worked for us. He made the final oil change in my driveway, as his "dooryard" was too full of customer's cars and trucks.

On the spark plug thread issue... If I were to find a mechanic, maybe one a bit unfamiliar with the V10 and that issue, I'd want to be sure I and he were on the same page should he have to remove a plug for a compression test. Don't want the test to create more problems. If memory serves, that Web site I wrote about in my first post also has a post telling how to service the spark plugs.

I forget if there was a long-term fix that could be made to the threads in the head; if there is, now would be a decent time to make that fix (assuming the OP decides to keep the engine). Anything to keep the plugs from blowing out at repair-plus-1,000 miles should help the OP sleep better.

[johnpsat]

I may get bashed for saying this but try running some SeaFoam through the intake. If it does nothing your only out about $8, but if the valves have a ton of carbon on them it could help. I've seen it do wonders to some old engines.

[JacobSyndeo]

Originally Posted by sibe

As far as the issues you have... the misfire on 3,, verify compression that tells the story.. Valve issue is known possible thing on a v10.. leaky manifolds dont help valves.. they can attribute to the o2 codes and lean readint but,, the low compression is major issue,

The mechanic called and confirmed low compression on cylinder 3 late this afternoon.

Originally Posted by donr103

Slide under her.. and check exhaust.. see if po removed cats.. see if the sensors are even there.. po may have taken off e gr valve or disconnected it.. that is where I would start..

The mechanic called this afternoon and mentioned that the cat was not in the best shape either; recommended replacement. It's still parked at the shop at the moment, so I can't confirm right now, but I can tell you the exhaust smells like the cat is either absent or not in great shape. The latter is to be expected if she's been misfiring for a while. The mechanic also said that if I don't replace the cat, it could become a fire hazard, and that the increased backpressure could also cause the engine itself to blow. If these risks are real, I'm considering a delete. (I'd of course prefer to have one, but they cost thousands!)

Originally Posted by donr103

next.. grab a book on Ford v10 engine.. and basic automotive repair book for 2000 Ford excursions.. with v10.. same eng and trans.. I like Haynes and Chilton.. after reading.. do basic tune up.. even if you put new engine in.. you will need these parts..
Do the engine yourself.. save 15,000.00 get 2000 era v10 out of salvage yards.. look at visione rv salvage yards in ky . There are probably closer salvage yards near you.. they only need basic tools to pull one..
Good luck and keep us posted

Thank you, I'm definitely considering doing at least some of the work myself, assuming the tools and repair information is readily available. TBH, my main concern with a DIY replacement is the sheer weight of the engine; I don't have any way to lift even a 1.5L 4cyl, let alone a v10. (Especially considering that said V10 has a ceiling above it; the hoisting equipment would have to be set up inside the RV's cabin or something!)

Originally Posted by l1v3fr33ord1

I note that the OP's first post implies he was told there was a valve/compression problem on cylinder #3, but nothing in that post says to me that the OP has had someone confirm there's a valve/compression problem. I think that on these V10s a misfire can result from a failing coil pack (as "baraff" mentioned), probably more often than a valve problem. I could be incorrect about this, though.

Another sign that makes me wonder is the OP doesn't report any obvious stumbling or power-loss symptoms.

I got a call from the mechanic this afternoon confirming the low compression. As for stumbling and power loss, the former may not be noticeable due to the fact that it's only 1/10 of the cylinders, and the latter may not be noticeable since I don't have much of a point of reference to compare it against. The closest vehicle (in terms of size/weight) I've driven was a 15' fully-loaded U-Haul with a trailer towing a Honda Civic, and this feels about the same as that.

Originally Posted by johnpsat

I may get bashed for saying this but try running some SeaFoam through the intake. If it does nothing your only out about $8, but if the valves have a ton of carbon on them it could help. I've seen it do wonders to some old engines.

I've heard the same! Not sure about the possible downsides to this, however. I don't imagine my cat will love it, but there's probably not much left to it anyway. Maybe some others could chime in on this.

[twinboat]

You can read up on cam followers to see if that sounds like something you can check out on your own.

[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..

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..

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...

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..

I have a exhaust leak on a vehicle now and it give mixture 1 and 2 imbalance and downstream converter inefficiency... I will temp weld leak and retest before chasing a weak converter,, plus the moter I have has 285K and uses some oil so, I wont work and be happy.. LOL