lexmonster

We picked up our 2008 GT after having been in the body shop for a rear bumper repair, and the car seems to be sluggish and low on power; but not dead. Took it to a local mechanic that calims it is low oil pressure, that there is no way increase pressure without engine overhaul or engine replacement. Also says the problem is in the VCT, but says that replacing the selenoids WILL NOT fix it. Is this guy full of it or am I going to have to buy a new engine. Any ADvise would be appreciated.
Thanks

NJ3

AutoXRacer on fnsweet had the same thing happen, he also has a 2008. Looks like you're in the same boat and may need a to replace or rebuild the engine. Click the link below.
http://www.fnsweet.com/forums/showth...607#post720607

bob

Did the mechanic say why there is no way to increase oil pressure?

I can't fathom why you would need a complete replacement if the VCT has failed?

This all seems sketchy to me, then again I'm the sort of person who likes a bit more thorough explanation. Did the VCT fail and damage the pump? Are the bearings wiped? the lash adjusters damaged and so on.

If the soleniods have failed and no other component is damaged then I dont see how this is a complete engine failure since cam timming has remained static and not caused an interference problem.

Thats if the problem is VCT related?

Honestly I'd check around, perhaps with the dealer and see if you get a different diagnosis. Just looking at one of Ford's flow charts, lack/loss of power doesn't list a critical failure of the oil system without throwing some sort of DTC, although a VCT failure can lead to a loss of power without throwing a code, as can the throttle position sensor, exhaust problems and so on.

jadedpony

Wouldn't your 2008 still be covered under the 100,000 mile, five year factory powertrain warranty even if the engine needed to be replaced

05YellowGT

If this is only on 08's , I wonder if it's related to the change in head design for the spark plugs ?

ford20

Except 09s and 10s have the same heads

If you were low on oil pressure then the tensiners on the chains might not have also been fully tensioned causing the chains to loosen up and maybe skip a few teeth on the sproket and rattle around a bit. Maybe that is why he was saying some engine overhaul since you basically have to take the entire engine apart to inspect the pieces and make sure they are not damaged but the more pressing issue to me would be what caused the low oil pressure in the first place.

houtex

I am having a major struggle with this. And I'll say this right out: I'm NOT an expert, but I've been poking about on the VCTs to understand how they work, and how you know they're NOT working...

If the VCTs or the Timing were off, you would know it. The car would not only have bad power, but also would run like complete crap or make hella noise. Neither of these are the case, if what the OP describes is accurate. Is it accurate, OP, or are you leaving out the hella noise, running rough issues?

The oil pressure causing no power? Only if the VCTs aren't moving. This is solenoids or bad VCTs or bad oil pump.

Now for the VCTs or Solenoids... the engine does NOT have to be rebuilt... but you DO have to know what you're doing to replace the VCTs. Solenoids are relatively easy to do.

The oil pressure, if it is that, is the oil pump. The oil pump procedure:
http://iihs.net/fsm/?dir=165&viewfile=Oil Pump.pdf
Basically, sorta kinda, indicates a rebuild. The oil pan has to come off, the timing components (cover, tensioners, chains, followers, all that) has to come off, the oil pump can THEN be replaced... so, in essence, a partial rebuild of the engine. It *can* be done in vehicle, according to the document, but... yeesh. WHO DESIGNS THIS STUFF?!??

But again... it's not describing a VCT/Low Oil Pressure situation. AND your car would be highly ticked off at no/low oil pressure and would SAY IT ON THE DASH. This is why I believe it's not the oil pump. I believe it's a bad solenoid or a bad VCT. OR there's a blockage TO the VCTs.

In any event, I don't think the guy's made a correct guess. Take it to a Ford dealer and don't tell them *anything* about what the guy said. You should be under warranty, unless you bought the car in May 2007.... was that even possible?... and so they should fix it period. No worries, except the hassle of getting it done.

I also went here, and the section you want is Chart 8 in it:
http://iihs.net/fsm/?dir=9&viewfile=...tom Charts.pdf

Look at all these items it could be. AT fluid, knock sensor... all kinds of stuff.
The pinpoint tests stop at H, so you may have to Google for the rest. Like in the case of the VCTs: http://www.google.com/search?&q=2005...npoint+test+hk, which another side (3rd link down at the moment) shows all the crud that could be needed to be checked.

I dunno if that helps, but it sure says "maybe he's right" now that I've done the legwork on it...

Man. I'm scared now.

cdynaco

5/60k

Why not replace with a larger oil pump if it has lost pressure/volume somehow?

Does using lockouts on the VCT change anything concerning oil pressure?


Never heard of this.

05YellowGT

[QUOTE=ford20;6366938]Except 09s and 10s have the same heads

but most 09's and 10's probably don't have as much mileage and since the link above says it's cam wear it just may not have appeared yet

ford4v429

low oil pressure is sometimes caused by a spun bearing. pull the oil filter, carefully cut it open with a utility knife and stretch out the media. if its not full of metalflake, find a different mechanic. if its got a lot of metal in it, thats real bad... low oil pressure wont allow the VCT enough force to do anything. AFAIK the oil 'pressure' gage in these cars isnt real...read somewhere the sender is actually a switch, gage is just a fancy idiot light placebo...might not show if any pressure exists.. know when my chevy 396 spun some bearings, the idiot light never came on, but the gage showed only 10 psi instead of 40 (was in a halfbreed '81 D150 pickup, Dodge idiot light switches must be under 10 PSI). oil filter was like metallic paint inside...

I dont think the cam chain tensioners can back off- might be misunderstanding, but always thought they ratchet out only- never a reason for them to retract, and engine could *possibly* be reverse rotated by say parking uphill without parking brake= slow reverse roll= negative oil pressure, loose chains, jumped timing, etc...
actually, never thought about this before- that *might* possibly be a VCT failure contributor too- parking on hills allowing the engine to turn backwards a bit while sitting there...thoughts?
Tim

cdynaco

That is a good thread. Thanx

AutoXRacer had the failure at 64,500 miles. "I've always used 5W-20 Mobil One oil with Mobil One oil filters..."

As for no cam bearings I don't know how uncommon that is - afterall, they only turn at half the rpm of the crank and basically, under cam rotation, the journals have a constant pressure - unlike the connecting rod journals on the crank that are getting slammed each stroke. And under normal circumstances, the cam journals are floating under a film of oil.

cdynaco

There is also another thread on an issue with some V6 cams where the TSB shows how to fix an engine tick. No concern is mentioned about no cam bearings.
https://themustangsource.com/f801/la...2/#post6359030

ford20

My whole thought process on this was that it was Occam's Razor and the simplest explanation that I was thinking of was a worn or broken Oil Pump. So what would happen is the Oil Pump would pump the oil into the engine and into the tensioners thus expanding them. On the 3V engine the plastic tensioners are expanded by oil pressure and sealed against the block by a gasket compared to the 2V steel tensioners which are sealed to the block of then engine based on pressure or force.



Now once the oil pump has either failed or has been clogged or it's performance diminished in some way it might cause the tensioner to loose pressure it allows the tensioner to retract even slightly and cause some slack in the chain. Once the chain has some slack in it even a little bit it could skip a tooth thus throwing off the timing of the engine causing it to have a rough idle and loose some power which would be one of the symptoms that the OP has described. Also the VCT on these engines run on oil pressure which would again cause the engine to basically act like a 2V V8 as the cam is not rotating to effectively give you the best angle to make the most power at that particular RPM.

Or once the oil Pump failed it sent a piece of the gears somewhere through the engine and possibly clogging up the oiling passages on the cam thus blocking the flow of oil to the cams. Once the oil flow has been blocked it burnt out the solenoid thus causing your cam to mess up and give you such the choppy and low power feeling.

Now IIRC from spending the last ... Oh 8 months researching cams and oil pumps for a nasty N/A 3V build the only real options here are to go get the FRPP oil pump which is the exact same as the ones used on the 3V and the same as the GT500 but at a cheaper price. Or he could run the Melling High output Oil Pump or the FRPP with TSS Billett gears which would be overkill in my opinion on what I assume is an otherwise stock to some what stock engine. Lockouts shouldn't have any effect on the oil pressure of the engine as all they are doing is preventing the cams from moving and they aren't blocking any oil passage ways on the cams. All you are doing is preventing the cam from spinning and rotating and fully locking it in a retard or advanced position.

As far as taking apart the engine, it can be fairly easy with a lift as all you would have to do is raise the car and drop the K-Member and from there just take apart the engine. But if it was me I would make sure the heads and cams and oil galleys and passage ways of the engine have been thoroughly cleaned before putting the engine back together just to make sure if the oil pump failed and the gears went all over the place. And if you wanted to be overly safe you can run the FRPP oil pump with TSS gears in it, as the Melling Oil Pump can only be used with lockouts since it doesn't flow enough oil to work VCT. Even re-timing the engine would be easy as he would be running stock cams without using limiters and can just line up the sprockets with the marks on the timing chain.

area5179

I have an 05 GT and had something similiar happen to me last year. Check engine light came on and I had some engine noise that sounded like I had more aggressive cam istalled. Took it to the dealer and they said that it was low on oil pressure and readi about 24 psi. They dropped the oil pan and found pieces of the timing gear guide in the pan. The guides were made of plastic and where in large pieces in the pan. Also the tensioners had failed. After an almost 4k repair pretty much the entire timing setup everything is good as new and have had no issues. I always used Royal Purple 5w20 and replace the filter with every oil change

area5179

i did strat a thread with the check engine codes that came up.

bob

Isn't the stock pump a powdered metal gerotor?

300angryhorses

I'm having the same problem, and threw a P0022 code. In the Autozone parking lot, replaced one VTC solenoid and the MAF, cleaned & disconnected/reconnected everything possible, & reloaded the modded and stock tunes, but the problem didn't go away.

The symptoms are similar to what has already been reported in this thread. At cold start, the engine is fine. As it heats up, +100 degrees, it surges and idles down low and then runs rough with tapping coming from the valve covers. It sounds like it has cams with a mean lope, but mine are stock. Power is weak and I have to give it a lot of gas to get the RPMs up and get it to move. There is a gas/foul smell and carbon deposits coming from the exhaust.

I pulled and checked the VTC solenoids by connecting them to the battery. They click and behave similar to the new one.

With a mechanical gauge, the pressure reads 50 psi at 2000 rpms. I've read in the Ford specs and Haynes that it should be at 75 at 2k rpms. It idles at less than 10 psi after warming up, but 50-60 or so at cold start.

I had it towed to my place, and I'm in the process of replacing the oil pump with a Melling 10340 now. One question that I have about the Melling is that it came with a 60 psi relief valve spring and an 80 psi relief valve spring. The instructions that came with the pump say that 60 meets that stock specs on the 4.6. I called Melling and the tech said to use the 80.

Any advice/help would be much appreciated?

cdynaco

I'm guessing here... but the tech probably is saying 'why buy and upgraded pump and hold to stock pressure'? I don't think extra oil pressure would be a problem.

Hopeufully other's will chime in.


Keep us posted if this resolves the issue.

AlsCobra

Not really familiar with the VCT system or controls. Easy way to bump up oil pressure to rule out a pressure issue is running a heavier oil. 14w40 20w50 one of these should do it. It won't really hurt the engine by using a heavier oil. Especially one with higher mileage. Main and rod clearances will wear in time and lower pressure. 5w20 is a really thin oil and have never agreed on ford using that thin of oil. It's gets them through the warranty period without sludge issues though. I would try a fresh oil change with 15w40 first.

300angryhorses

Ok. I installed the oil pump, and the pressure is up at idle (25 psi) and 2000 rpms (75 psi). However, the rough idle and knocking still happens when the engine temp gets above 105-110.