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Mohawk Enthusiast
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35 Posts
Discussion Starter · #1 ·
I need some opinions guys, this sound showed up maaaany months ago, but I never paid any attention to it because I could only hear it when I shut it off after driving 15+ minutes, but my last trip in it I drove it 60 miles and after 25+ minutes I could hear it when I let off the throttle which has never happened before, I messed around with it some and I could only get it to make the sound when fully warmed up, either at idle, or below 2000 rpms in 5th when I let off the gas.

The sound is definitely in the passenger’s valve cover, I took a stethoscope to the engine and it’s loudest on the passenger’s side valve cover

http://youtu.be/ucZcZq1-lp4

Car is a ‘99 GT, with a 2005 grand marquis 4.6L with the cams/intake from a newer mustang with the aluminum “bridge” on the intake, 01-04 I believe? So more or less it’s an 04 GT engine.
 

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Mohawk Enthusiast
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35 Posts
Discussion Starter · #3 ·
See I was thinking oil/lash adjuster too. I’m running castrol 5w20 because that’s what the Grand Marquis calls for and I’ve used castrol GTX for years with great luck, but I’m wondering if maybe this particular batch wasn’t thinner than usual and it needs 5w30.

As for oil pressure I’m running the stock dummy gauge, but it’s reading “enough” pressure to keep the gauge on

Also: I took the valve cover off earlier today and visibly I can’t find anything wrong. I initially thought when I rebuilt it 4 years ago I forgot to loctite the cam cradle and it came loose, but that’s not the case.
 

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King Trashmouth
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21,891 Posts
You might check and see if any of the rockers are loose to the touch.

I would get a mechanical gauge on it. The gauge on the car is just a pressure switch; above 5psi it shows fine, below it shows low. It's a pretty low threshold. I would see if 5w30 quiets it up. Keep in mind the engines were originally developed for 5w30, and they switched to 5w20 to improve fuel economy.

My thought would be that when you experience it, which is low RPM when oil pressure is lowest, at hot temperatures when pressure is also lowest, there isn't enough pressure to pump up the adjuster. 5w20 would only aggravate it. Whether an adjuster is failed or not is another matter.
 

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Mohawk Enthusiast
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35 Posts
Discussion Starter · #5 ·
Ahhhh, I didn’t know that about the fuel economy thing. I was under the impression that particular engine was designed for the thinner oil.

I have a glowshift in my truck I can swap over temporarily

Sounds like I need to put the valve cover back on, install the gauge, give it a try, then change the oil and see what happens.

Thanks for the input dude, I’ll try it and get back.
 

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Registered
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6 Posts
Rattle

Most of the time when a high mileage motor is warm and you hear a rattle when lifting off the pedal, you are in all likelihood hearing the rods when on the pedal you have them loaded but on the lift, there is no load and any extra clearance will become noisy. like the drag strip watch a majority grenade on the lift. An engineman with a stethoscope and or a kit to measure if the bearings are leaving brass in the oil the underlay of a bearing. to limp with thicker oil easy on revving and when you lift off the gas roll out gradually to lessen the sudden harmonic vibration a 4.6 is only allowed 2 grams of balancing that's not much. A great time to baby it as you start a fresh short block build. Be picky on this joes machine shop usually has no idea of the tight clearances and many don't have the equipment to properly machine it. if you have questions message me.

Dirtymikehttp://www.moddedmustangs.com/forums/images/ModdedMustangs_2015/smilies/tango_face_sad.png

---------- Post added at 02:14 AM ---------- Previous post was at 02:10 AM ----------

Oh, don't let ppl tell you this or that additive will fix it. IIf a bottle fixed engines and transmissions then mechanics wouldn't be needed just a heads up
 

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US Air Force (retired)
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13,542 Posts
You motor was designed for 5w30 conventional oil. Here is a copy of the owners manual.
http://shnack.com/docs/1999_owner_guide.pdf

As was mentioned before, Ford changed to 5w20 conventional oil in 2001 because of the fleet gas mileage requirements and the fines associated with them. 5w20 is actually too thin but it is fine if you drive like grandma. The '99-01 owners manuals also say to run 5 quarts of oil. Ford changed that in 2002 to 6 quarts of 5w20 blended oil. The only change they made to the motor was to shorten the dipstick.
http://shnack.com/docs/2002_owner_guide.pdf

The problem with the 4.6L motor is the oil return passages are somewhat restricted and it is possible to pump the oil pan dry if you are a quart low and running high rpms. The oil pan will easily hold 8 quarts of oil without interfering with the crank and it is recommended that you run 6 quarts of oil. Some forum members run 7. I got tired of looking at a dipstick that said I had overfilled the oil so I did the dipstick mod. I bought a 2002 dipstick. It now takes 6.5 quarts to reach the full mark when I change the oil filter.
http://www.moddedmustangs.com/forums/96-04/542817-new-6-qt-dipstick.html

Here is a thread on oil. My motor has 210,000 miles. I have always used full synthetic oil. When I first bought the car it was full synthetic Quaker State 5w30. Later, I switched to full synthetic Mobile 1 0w30 for the cold start protection. Wear and tear make the tolerances inside a motor larger. Larger tolerances require a slightly heavier oil. When my motor started using a little oil (one quart per 3,000 miles) around the 200,000 mile mark I switched to Mobile 1 0w40 full synthetic European blend for two reasons: First, it stopped the oil usage. And second, it contains the ZDDP level that was in oil when our motors were designed.

Here is a fairly comprehensive thread about oil.
http://www.moddedmustangs.com/forums/96-04/292127-grade-oil-should-you-use.html

I have had hydraulic lifters (lash adjusters) lose their prime when the motor is shut off. They clatter like crazy on a cold start until the oil warms up and starts flowing. I've never had the clatter after the motor was warmed up.
 

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Super Moderator
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13,581 Posts
Im over here thinking you might need to start with a exhaust sniffer or stethoscope and inspect the exhaust manifold for a leak on that side and totally rule that out.
 

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Mohawk Enthusiast
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35 Posts
Discussion Starter · #9 ·
Man you guys don’t skimp out on replying It’s good to see some life on a forum though.

I’m just gonna brush over what some of you said because I’m squeezed for time today.

The link for the 99 owner’s manual isn’t really relevant as I mentioned before only the body and electronics of this car is a 99. The engine is a complete 05 Mercury Grand Marquis longblock with about 136k of pure babied miles (Don’t ask why, I don’t know lol. The previous owner blew a headgasket and put that engine in) and the intake and cams are from a later I guess 01-04 or 02-04 mustang, and the rest of my drivetrain came from an 03 Mach 1 with the noisy ass tr3650 lol

As for oil I’ve run 6qts of castrol 5w20 for 4 years (ever since I put the car back together after refreshing the engine and manual swapping it) with no issues until this showed itself a few months back, but even then it was quiet and of little concern. I just passed it off as the trans.

I also know the lifter tick on cold starts. My 98 F150 has 220k on it and it does the lifter tick until you get it warm when it’s bitter cold or it sits for a few days, but this is different. That tick gets faster when you rev it, this one just goes away/gets quieter.

Same for exhaust leak, I know the infamous 2v manifold leak sound and it’s more of a tick. As you can see in the video I posted it’s a clacking or a rattle. Kinda sounds like a rocker arm just flopping around in there.

But yeah, I’m no noob, i just like to pick other people’s brains while I’m trying to figure it out myself, so even if I seem like a dick I appreciate the replies and info. Every little bit helps in the troubleshooting process!
 

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Premium Member
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24 Posts
Dont rule out a failing timing chain tensioner. It could be going soft, causing slack in the timing chain and leading to that noise at/around the cam gear. Easiest way to tell is pull the valve cover and if you can feel slack in the timing chain with you fingers, the tensioner is bad.
 

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Mohawk Enthusiast
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35 Posts
Discussion Starter · #11 ·
Dont rule out a failing timing chain tensioner. It could be going soft, causing slack in the timing chain and leading to that noise at/around the cam gear. Easiest way to tell is pull the valve cover and if you can feel slack in the timing chain with you fingers, the tensioner is bad.


Just checked it and it’s solid on both sides
 

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Registered
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790 Posts
I would see if 5w30 quiets it up. Keep in mind the engines were originally developed for 5w30, and they switched to 5w20 to improve fuel economy.
How dafuq did I not know this?!! glad I check this thread.
 
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Mohawk Enthusiast
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35 Posts
Discussion Starter · #13 ·
So, I’ve been busy and things keep coming up, but today I drained a quart of oil out bringing the engine down to about 5 quarts, and put about a 3/4qt of Lucas oil stabilizer (aka snake oil, aka oil thickener lol) and the noise is almost non existent, it’s intermittent and very faint only at idle now.

I think it may be a rod bearing though, sadly it’ll be awhile before I can tear it apart and find out, but I will keep driving it around town some so if it slings a rod I’ll let you guys know and post pics of the carnage
 
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