Melling M340HV A Problem with VCT Solenoids...?

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SafariGoneWrong

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Hi all,

No question here, just posting an exasperating and totally unexpected outcome after swapping out an M360 for an M340HV. 2006 Expedition.

Quick background, all timing components along with lash adjusters and roller followers replaced in 2017 at 100K miles due to a bad phaser. At the same time, replaced the OEM oil pump with the Melling M360. At the time, the M340HV wasn't out yet and FordTechMakuloco and Jasper were singing the praises of the M360. I had no problems 100K - 120K mi. except a lash adjuster started making dinking sounds but only when cold at 120K mi. Completed a replacement of 24 lash adjusters (Melling to Motorcraft) last weekend along with the swap of the M360 to M340HV at its current 124K mi. I never liked the idea of 80 psi oil in the engine and thought it much wiser to go to a pump with a 60psi relief. Hmmm.

After getting the engine put back together, the M340HV pump primed in no more than 20 secs of cranking (the M360 wouldn't prime from cranking, only after engine start). It started fine with clacking lash adjusters and quieted down when warm. Took it for a test drive next day after the engine was warm and it ran great/normal. The next morning, drove it to the grocery store with a cool engine when power suddenly reduced at about 30 mph under easy acceleration. It would barely idle and lacked power. Turned around, made it home and put FORSCAN on it. Advance Error on both banks was -53 degrees. Disconnected VCT solenoid harnesses and no change. Stopped the engine, restarted with same behavior. Done. Had to assume a mechanical problem based on codes, observations and all VCT parameters in FORSCAN. It's in my garage now, apart, and am about to put the front cover back on after installing an M340. First thought was a defective harmonic balancer bolt let go and the woodruff key sheared, allowing the crank sprocket to rotate. Nope. Just fine. Timing is fine. Checked the VCT solenoids with 12V and they seemed ok...sort of. Phasers show locked at the default position (the middle tang is aligned with the L). I removed both phasers, replaced the one with 24K mi so both phasers now have a total of 1.5 miles on them. The only thing that changed from before to after is the oil pump (and Motorcraft lash adjusters). FORSCAN Lite when driving shows the VCT duty cycle is highest under light-moderate load at low-mid range rpm. That's when my stuff let go.

All I can think of is the M340HV smashed the solenoids with pressure it couldn't handle and they stayed open flowing oil, fully retarding both phasers. I know the relief is 60 psi but what if the bypass is max'ed out? Cool, thick oil... Now you have unregulated pressure in the engine... I'm running Mobil 1 5W-30. To me, the M340HV has to be the problem, especially considering how a Melling HV pump burst the oil filter in my Bronco's 4.9. It was a Motorcraft FL1-A filter.

C'est la vie.
 
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SafariGoneWrong

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Thank you whtbronco, always appreciate your posts. I have to provide 2 more observations. With the front cover off and rotating the engine by hand, solenoids removed, oil spurted out of the right side solenoid housing such that it launched upward and landed near the fender well. Never saw that before--it was impressive. (Also, when priming the Bronco's Melling HV pump with my DeWalt drill, it labored like it was boring with a 2" spade bit into a 4x4. It was concerning...sort of glad the filter blew up because I wouldn't want that pressure running through the engine nor the strain on the distributor/pump drive shaft.) Apparently I'm the only person so far with any experience the M340HV may not be an ideal upgrade.
 

whtbronco

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I know that HV oil pumps are common and I too have installed them. That said I have always wondered if it's really a good thing in all cases. With high volume we need more space for the oil than we needed before, I mean we have more oil going through the engine now. So we need more space between the crank/rods and bearings, enough oil returns to get the higher volume oil back to the pan quickly enough, that kinda stuff. I don't know, just things I ponder.
 

David E

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Hi there,
Looking at getting the timing done with the whole kit replacement as well as ruler followers. Also got a set of spark-plugs to replace old ones. Mine is an 05 with about 200k on it. All parts are from ford and cost me around $1800 (no pump) They wanted 5k just for labor.
Looking at the pumps I was also worried that my engine might not be able to deal with HV or High PSI (80psi). To my best understanding the M340 is the stock right? Should I just go with stock?
Would love to not open her up again after the work is done. (doing it myself)
Also when looking at replacing all 24 rollers would that be easier with just removing the Cams? Or should I worry about anything there popping. Thanks so much for all the great information in this forum.
 
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SafariGoneWrong

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The roller followers first. Doing it by the Ford Service Manual they go back in after you get the cam timing right and there's no shortcut. Each valve spring is compressed after the cams are installed and putting the follower back in is an adventure for each valve--sometimes they're easy and other times they just want to roll on their side or get hung up and make life hard. You'll definitely want a telescoping magnet. Coming out is a different story--remove the designated 3 from each bank with the compressor and lift the cam out. Don't forget the lash adjusters. I'd get the OTC 5.4 valve spring compressor, it's pricier but I don't want a cheap tool for a time consuming and critical job. And to replace the lash adjusters the cams have to come out. The FordTechMakuloco videos are invaluable but there's no substitute for the service manual. Ford phasers now come with instructions that are straight from the service manual it appears.

Your question on oil pumps. I believe Ford designed the oil pump with enough capacity to take care of a reasonably worn engine. Lots of stories out there of 5.4 3V engines with low oil pressure. Who knows. My own experience says Melling HV pumps aren't suitable for what I'm doing and the condition my engines are in. The Melling M360 I had in the engine for 20K miles never presented a problem but I didn't like an 80 psi relief. But it seems I'm the only one in the world with what I think is a HV pump issue on a 5.4 3V; however, the evidence is compelling. I put in a Melling M340 after my experience; the front cover and valve covers are on and hope to finish the job in the next two weeks/weekends.

Here's an unrelated hack. When putting the valve covers back on, use a length of masking tape to hold the rear bolt up so it more easily clears the aft journal cap. Makes life much easier, especially on the right bank.
 
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SafariGoneWrong

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Following up on the M340HV oil pump. Finally got the Expedition of the garage (last week was spent on brakes issue) and out for a test drive today. It now has the Melling M340. This time both banks didn’t retard 53 degrees almost instantly after the first stop sign. I’ll stand by my original diagnosis that the VCT solenoids couldn’t handle unregulated oil pressure. After the debacle a few weeks ago, I re-read the oil section in the shop manual and recalled the VCT system gets the pump’s unrestricted output like the bottom end. The oil restrictors in the heads are for lash adjusters, cam journals and tensioners. Anyone considering a timing job or other reason to pull the front cover off should give serious thought to staying OE for the oil pump to include Melling’s stock replacement.
 
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