start-up rattle, 4.0l SOHC

I have two 2000 Explorer XLT both have the SOHC V6.

They both make the same noise when first started (cold start). It lasts only a second or two at most. It is a noise that resembles a diesel starting. I have always thought it was normal for the 4.0 SOHC. I don't think I've ever been around one that sounded any different. I have always thought it was tappet noise until the lifters were pumped up. It has hydraulic lifters, right?

I could be ignorant and happy believing this is normal. One has 115K miles, the other 83K. The 83K motor has a new noise that got me reading some frightening threads here. On two occasions I have started the engine (warm starts) and been confronted with a sharp tapping/rattle sound that does not go away until the engine is shut off. It doesn't happen every time. I have not had it happen on a cold start yet. It is a slower rattle than the start-up clatter I described above. It sounds like it could be one bad hydraulic lifter. But in reading through some posts here, I fear it could be timing chain related.

Can anyone confirm the normality of the cold start-up noise?

Has anyone experienced the intermittent new noise?

Would a broken plastic chain guide bouncing around under the timing cover make this kind of noise?

83K seems like short life for a hydraulic lifter, if that is the cause. This motor has had all scheduled maintenance.

The cold start rattle is most likely the tensioner that theads into the head they are hydraulic and leak down after sitting for a while.The 4.0 sohc doesn't have lifters they use hydraulic lash adjusters, they do not ride on the cam like lifters.

rockers & adjusters

The SOHC V6 has roller rocker arms and hydraulic lash adjusters. Either could become noisy due to wear or the adjusters could be noisy due to dirt. The frequency of the noise from either should differ from the frequency of chain rattle. Valve train noise is more like a ticking.

Although rare, some forum members have experienced timing chain guide failure as early as 40,000 miles.

You may want to consider an engine flush when it is time for your next engine oil change. Are you using synthetic oil? It gets to the chains/guides faster than conventional oil at engine start. I buy a quality filter with an anti-drain back valve.

Thanks for the reply. As I said, I don't think I've been around one of these motors that did not have the cold start rattle. Leak down of a hydraulic tensioner makes sense, even new ones will leak down, albeit a bit more slowly. The cold start rattle wasn't anything I was worried about until the new/different symptom started.

2000StreetRod said:

The SOHC V6 has roller rocker arms and hydraulic lash adjusters. Either could become noisy due to wear or the adjusters could be noisy due to dirt. The frequency of the noise from either should differ from the frequency of chain rattle. Valve train noise is more like a ticking.

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Never having had to tear into the motor on any of our 4 Explorers, I have not studied the valvetrain pictures. My experience under the valve covers of OHC engines is limited to the VW water cooled engines. I'll crack open the manual and start calling things be the right names.

The intermittent occurring warm start noise is a very steady tapping/ticking. Around 5 Hz at idle. Basic math tells us that each valve opens 5 times per second at 600rpm. Seems like we are barking up the right tree.

The 83K rig is new to me, but I bought it from the original owner and have its entire service history. Unlikely that it has had synthetic oil, but 5w-30 changed like clockwork.

Is there a particular filter you use, or one that I should avoid?

I think I have found the cheapest fix for your problem. On cold mornings I bump the key on my 2000 with 187,943. In other words hit the starter briefly to spin the motor but don't let it start. I do this once or twice depending how cold it is and it seems like it pressurizes the tensioners and prevents the ugly noise. I still plan on pulling the motor and fixing it proper when I can be sure my fingers won't fall off from frostbite.

oil filter

I have a remote full flow oil filter (Mobil 1) and a remote bypass oil filter (Amsoil). Both are vertically mounted behind the front bumper with the openings up so I have no drain back even if the check valve sticks open.

rattling engine

svt4cam said:

I think I have found the cheapest fix for your problem. On cold mornings I bump the key on my 2000 with 187,943. In other words hit the starter briefly to spin the motor but don't let it start. I do this once or twice depending how cold it is and it seems like it pressurizes the tensioners and prevents the ugly noise. I still plan on pulling the motor and fixing it proper when I can be sure my fingers won't fall off from frostbite.

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Hi im new to the site.Im replying to the guy with the engine noise.I have a 2002 4.0 sohc engine.My motor started with a rattle in the morning, but as time went by the rattle got worse.I found out that the timing chain had ripped a hole in my vavle cover.I pulled the motor to find that my chain guide was shattered into 20 bits an peices in the bottom of the oil pan.ive replaced front an back chain guides an chain for under $250.Ive put the motor back in the truck to find another problem.when the chain guides gave way.The fragment that were in the oil pan clogged my oil pump which made the hydralic cam tensioners quite working.Thats what made the timing chain skip a couple teeth on the cam which now i have found out that i bent some valves.Still working on it i will let you know how it goes.(a little advice if you hear a rattle you better check it out)Plus im doing all of this on my own trying to save some cash.Ive heard to get this fixed it cost from 18-2500bucks

So I stared at my book for a bit. Does not happen to have a picture showing the relationship of the assembled parts. Based on the placement of valve stem and lash adjuster it appears that the rocker arm is simply suspended between the tops of those two parts, with the roller in the middle, riding against the cam lobe. Am I correct that that it is just held in place by valve spring pressure? Text describing the rocker arm removal says use tool to compress spring (special tool shown in place) and remove rocker arm - no mention of any other retaining mechanism. Interesting that valve travel is much greater than cam lobe.

misplaced rocker arm

I recall that one member pulled his valve cover and found a rocker laying on its side between two cam lobes. The valve stem keeps one end of the rocker in place. The lash adjuster keeps the other end in place.

I have a 1999 4.0 SOHC. With over 170,000 miles I have done very little to the engine. I am running 5w-30 Amsoil. I have recently noticed a very loud tapping sound coming from the driver side of the engine. It only does this shortly after the engine is shut down and restarted and only once in a while. It reminds me of listening to an old model A running. The noise sounds like it could be coming from the air intake area under the protective cover on the top of the engine. I was thinking a injector could be making the noise. I have been doing my own oil changes for the past couple years and have been using fram oil filters. I have also read that Fram filters can cause issues on start up due to low oil flow. Tonight I was planning on switching the fram out for a Motorcraft. I am hoping this might help if the problem is oil getting into the upper part of the engine. This engine has been making this noise on and off for a couple years with no drivability issues.

Rattle Chain

Hi, all.

After just received a 98 Explorer i noticed the famous Rattling from the engine.

What i'm wondering about is : Which of these chains is most likely to make this annoying noise. I just hope it's the ones in the front, so i don't have to remove the engine to get to the one in the back. Deliver it to a shop is out of the question due to the cost (Approx. 6000 USD in Norway).

It sounds like a Diesel engine the first 10-20 seconds and then almost disappear, but is still noticeable, especially around 2-2500 rpm, but i cannot locate the sound, if it's from the left/right/back or front.

Regards
Tommy

Chain rattle - most likely source

From what I have read on the forum:

Most likely: front jackshaft tensioner failure
Next likely: left front guide assembly failure
Least likely: right rear guide assembly failure

You might try removing the oil filler cap to help isolate but might be messy.

The most reliable way to isolate is to remove the valve covers and visually inspect but that's quite a bit of work.

I have a nice little rattle in the front too. Sounds like a loose exhaust but I dont hear any leaks. Its not consistent but seeing some of these posts have got me scared.. all this chains and stuff exploding in the oil pan and bending valves :S

I'm hoping to hell its a loose exhaust manifold or that rusted out heatshield problem...

Do you think the odds are in your favor ? Have you read the complaints ?
Maybe check youtube for the rattle sound for a comparison.
Best thing you can do is fix it before it breaks or sell it.

I called the 4.0 SOHC out on being junk yesterday and someone didnt like it.
I love Fords and have had and will continue to own and use Fords, just not junk Fords like anything powered by a 4.0 SOHC.
I do not really care for Ford 3.8 headgasket eaters either, I just dont like JUNK.

I highly doubt the odds are in my favour. My luck has never ran that way.
I did what you said and look over YT. Sounds like the timing chain tensioner. BUT my ticking rattle is not as bad and doesnt do it all of the time unlike those videos. Barely noticable during idle, gets a bit louder with higher RPMs but not much. I'll fix it before it gets any worse and hopefully the engine is saveable and preventable from future breakouts...

I haven't lost any gas mileage or power, which I saw some other people had problems with. Might have some luck there...

Another symptom I saw is RPM idle. Some people are lucky to idle 800, but have bad engine shake. Mine idles just above 1000 when stone cold and after a few minutes drops down to a smoothe 600-700. It does sometimes bounce below that then back up, almost to a stalling point, but I havent had that for awhile now and I think that part is my alternator. The POS alt is dieing ,my power windows alone make the engine lose RPM...

when I had my 250w RMS amp in there my voltage dropped to 12v everytime bass hit. My new powercell definitely helps, voltage stays in between 13.5-14, a little patchup till I find a nice H/O alt.

tsjries said:

I have a 1999 4.0 SOHC. With over 170,000 miles I have done very little to the engine. I am running 5w-30 Amsoil. I have recently noticed a very loud tapping sound coming from the driver side of the engine. It only does this shortly after the engine is shut down and restarted and only once in a while. It reminds me of listening to an old model A running. The noise sounds like it could be coming from the air intake area under the protective cover on the top of the engine. I was thinking a injector could be making the noise. I have been doing my own oil changes for the past couple years and have been using fram oil filters. I have also read that Fram filters can cause issues on start up due to low oil flow. Tonight I was planning on switching the fram out for a Motorcraft. I am hoping this might help if the problem is oil getting into the upper part of the engine. This engine has been making this noise on and off for a couple years with no drivability issues.

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mine does almost exactly that.... did you ever pin point whats up? my friend has a ranger with the same 4.0L SOHC as mine and his is in fact the injectors... hes got i belive a little over 200,000 miles on it as well

tsjries said:

I have a 1999 4.0 SOHC. With over 170,000 miles I have done very little to the engine. I am running 5w-30 Amsoil. I have recently noticed a very loud tapping sound coming from the driver side of the engine. It only does this shortly after the engine is shut down and restarted and only once in a while. It reminds me of listening to an old model A running. The noise sounds like it could be coming from the air intake area under the protective cover on the top of the engine. I was thinking a injector could be making the noise. I have been doing my own oil changes for the past couple years and have been using fram oil filters. I have also read that Fram filters can cause issues on start up due to low oil flow. Tonight I was planning on switching the fram out for a Motorcraft. I am hoping this might help if the problem is oil getting into the upper part of the engine. This engine has been making this noise on and off for a couple years with no drivability issues.

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The oil filter will make no difference. Fram actually has better flow than most. Check this out:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=315271&page=1

The motorcraft has an anti-drain back valve, but since it's mounted vertically on the 4.0 it makes no difference

Hi guys...

I am weighing in here with my story ...

bought this 2000 Explorer 9000 miles ago.. when we bought it we heard the idle rattle. After the oil change oh it got so much worse. So we figured that they had put some sort of oil in the crank case that quieted it down..

I put the best synthetic in i could find... the new pennzoi ultra.. it is very spendy but it really has made a difference.. they claim that this oil will clean up the engine cleaner than new, and i believe this from the results so far..

I still hear a very small amount of noise but nothing like what it was like.. So i am thinking after some time those hydraulic tensioner's got clean they started working a lot better..

I don't know yet how worn/broken the guides are, but i have gotten almost 9000 miles now out of this motor that i was sure was about to explode.

I am going to tear this motor down and do the needful, but for now the money i spent on this oil has made a serious change in the noise and my confidence of this motor..

I will update you all when i tear it down, pictures and all ... until then.. if you don't have the time or money to fix your motor, buy the best synthetic you can afford ...

Yep..had a similar situation as Janzwolf, only in reverse. I have had the rattle for well over 100K in my truck (160K now), but it has never been that bad compared to some of the ones I hear on YouTube. I usually run Walmart synthetic oil with Motorcraft filter, but they were out of the Walmart oil when I last went there and decided to buy Quaker State High Milage conventional. Well, I've been hearing the rattle more lately since that oil change. It still is not that bad, but I realized I can't be a cheapskate when it comes to taking care of this engine if I want it to keep going (Which it has been amazingly trouble free other than the rattle and a couple of IACs). Lesson learned!!