A new noise coming from engine compartment

olopezm · 07-31-2012, 04:59 PM

Hi guys it's me... again!

This thing can't seem to give me a break LOL.

We have been using 15w40 oil for years and never had a problem. I know it's too thick for these engines but we don't get such low temperature as people up north. Right now temps are between 70-86, it's been rainy and during winter it will get as low as 32 in the morning...

So you'll see, I decided it was time to change the oil, it was a bit over due, and decided to switch to 5w30 to see if there was any difference and to make the things the right way from now and on; well, there is actually a BIG difference, the engine isn't as loud as before, and the new fluid and filter (both motorcraft) made a tapping sound I had on cold starts go away, after many years with it!.

It idles great, runs quieter and has a 30% better fuel economy. What else coud somebody ask? This is where the ugly part comes. I don't know if I hadn't noticed before because the engine was noisier or what, but now I can hear a "weird" sound, sorry that I don't know how would you guys describe it,
at HOT idle, it seems to go away if I rev the engine (again, I don't know if the louder it's actually masking it rather than making it go away). It's running OK, hasn't taken any oil and there is no smoke coming out from the tailpipe; as I said the noise is only present after the engine has reached normal temperature.

I don't have much experience with these things, I don't know if it could be a lifter, a valve, rings, timing chain or what else!. I only get some occasional misfires and the LTFT for bank 1 goes up to +18 from time to time.

Here's a video of the noise; it seems more noticeable at the passenger side where the serpentine belt is.

http://youtu.be/Fp8FhPL3w2U

Anybody thinks this could be an exhaust leak? I've noticed that after the transmission was rebuilt, it will make a LOUD clicking sound minutes after I turn off the engine because of the exhaust pipes expanding/contracting.

Thanks in advance,

Oscar.

************************************
UPDATE September 11 2015

************************************

Skip all the diagnosing and go straight to the upper intake manifold. Remove it and, if you have the old 3 part version (upper and lower covers, and a baffle), take off the middle baffle, reassemble and test to see if the noise is gone. That's what solved my problem.

There's a redesigned (one piece) part from Dorman (615-277), get that.

Things I replaced to no avail:

Timing chain and tensioner
Camshaft synchronizer
Water pump
Belt tensioner

I hope this helps,

Oscar.

12Ounce · 07-31-2012, 05:29 PM

I would think an engine in good repair would run fairly quietly on 15w40 ... especially in a hot climate. I have used 0w40, and 5w40 ... from time to time, in hot weather, especially on round-country trips ... in my '99 3.8. I normally use 5w30 at other times. But have had no detectable noise issues due to oil grades.

You may have some issues with your oil pump or pick-up tube. I would be tempted to drop the oil pan and have look. The oil pick up tube may be blocked ... or it may be loose at the mounting, allowing cavitation air to leak in. The oil pump and pressure relief valve are on/in the front cover.

Could the scynchronizer be noisy? May need some drops of oil.

12Ounce · 07-31-2012, 05:46 PM

For some reason, I can't make the Youtube site work ... some internet setting screwed up, I suppose.

olopezm · 07-31-2012, 06:33 PM

Thank you 12Ounce, always good to read your advise.

Well, it's not that the engine is very noisy, it isn't; I would say it's a normal healthy sounding engine but there is a noticeable difference between 15w40 and 5w30 weight.

Synchronizer? Is that the one by the IMRC actuator? I used to think that one would squeal. That's not my case, I'm having a hard time trying to describe the noise, but I would say it MIGHT be a "tapping" sound just to give an idea. I never noticed before switching to 5w30.

Too bad you can't take a look at the video...

Oscar.

tempfixit · 07-31-2012, 08:40 PM

To mee he video seems low in volume even withn all settings at highest level so it makes it hard to tell, but to me it seems to be a tappet noise, Have you checked oil pressure with a gauge?

12Ounce · 08-01-2012, 03:00 PM

OK, I got my browser add-ons back working. And I listened to your "noise" ... not much, I would say.

Howabout removing the serpertine belt and listen again. Don't run it very long that way ... may need to play garden hose on radiator, if you are going to have it on over a minute or so. Watch temps!

To me it sounds like a noisy belt and tensioner. ... but it could also be a noisy chain.

olopezm · 08-01-2012, 06:33 PM

Thank you tempfixit, I've uploaded a new video; I hope this is a better one. I had the cellphone facing in the opposite direction, it seems better to me. I don't have a gauge for oil pressure nor have someone that I could borrow it from. Autozone doesn't rents those around here. Where should the tester be plugged in at?

Thanks again 12Ounce. I will check the tensioner for wobble during operation and remove the belt when the engine is at operating temperature. When I changed the belt around 11k miles ago, the tensioner felt strong but I guess its worth a look. If the engine is cold, there is NO noise other than normal operation.

Here's a second video:
http://youtu.be/19EaaVheFfA

During the louder moment I held the cellphone in the passenger side wheel well.

Oscar.

12Ounce · 08-01-2012, 07:11 PM

Well, as the engine warms ... the thermostat opens up and the coolant pump is more active. Could it be the coolant pump?

tempfixit · 08-01-2012, 08:46 PM

I can hear the noise better on this video Oscar, if removing the serpentine belt at operating temp does not eliminate the noise I would remove the oil pressure sending unit and use its port for oil pressure gauge. I would observe the oil pressure from cold to normal operating temp to see if the oil pressurefalls off dramatically, hopefully that is not the case.

olopezm · 08-02-2012, 07:47 PM

Thank you very much guys, it's always good to know you're willing to help!

I didn't drive the windstar today, but will do the test with the serpentine belt ASAP and post back.

12Ounce Would a coolant pump show any other symptoms other than being noisy? Wouldn't it be more like a bad bearing noise?

tempfixit I was thinking that a lower volume or pressure of engine oil (failing/starving pump) would cause the temperature to raise due to bad lubrication and increased friction. Is this assumption correct or not?. My cheap livedata scanner shows the ECT is at around 185 F. Am I running in circles?

Oscar.

12Ounce · 08-03-2012, 08:26 AM

There's no gaurantee how a water pump may fail. I've seen the impeller disappear due to poor coolant chemistry (caused by using clear water). Of course they often leak. The bearings can get noisey and wobbly. But I've heard of the impeller shaft snapping in two without much warning. So who knows?

olopezm · 08-06-2012, 09:15 PM

Quote:

Originally Posted by 12Ounce

There's no gaurantee how a water pump may fail. I've seen the impeller disappear due to poor coolant chemistry (caused by using clear water). Of course they often leak. The bearings can get noisey and wobbly. But I've heard of the impeller shaft snapping in two without much warning. So who knows?

Ah you're right man. In fact this engine overheated back in 2005 after the impeller disappeared, just like you said. We rebuilt it, installed it and overheated a few weeks later because there was still some air trapped in the system; so that makes TWO rebuilds for this engine...

If I remember right, the replacement water pump had a plastic impeller.

Today I got home and as usual the noise was present, I removed the serpentine belt as fast as I could (I hate such task with this engine), took me 10 minutes maybe and started the engine for a few seconds... The noise was gone; I thought I had found the problem so I reinstalled the belt to see if it would reappear but no, it didn't, even when the engine was still at normal temp. How much it could have cooled down in only a couple of minutes?

Now I'm at loss. I don't know what else to check. As I said before, the van drives fine and has plenty of power. I shot another video just after I reinstalled the serpentine belt. As you can see it sounds pretty healty, at least for me.

http://youtu.be/05A3M9MJNHo

What do you guys think?

Oscar.

12Ounce · 08-06-2012, 10:27 PM

I just set the parking brake, lift the hood and pull the belt off the closest puilley (alternator?) ... one advantage of Popeye arms. 15 secs max.

Did you check all pulleys to see how they feelth? (Is that a word?)

Have you tried running without a thermostat?

scubacat · 08-07-2012, 09:23 AM

12oz beat me to it. Especially the tensioner and idler pulleys, did you spin them by hand? Our van had a similar noise when the tensioner was on it's way out.

olopezm · 08-07-2012, 09:41 AM

Thank you guys,

Quote:

Originally Posted by 12Ounce

I just set the parking brake, lift the hood and pull the belt off the closest puilley (alternator?) ... one advantage of Popeye arms. 15 secs max.

Did you check all pulleys to see how they feelth? (Is that a word?)

Have you tried running without a thermostat?

Haha, yeah I know. I was able to do that two years ago when I still used to workout, haven't been able to since then. Yesterday I tried to do it, but wasn't able to pull the belt enough to clear the alternator pulley. Had to turn the wheels to the right and reach the tensioner with a 13mm wrench.

Haven't tried running without thermostat. I've been wanting to change the coolant and flush the system, but haven't had enough time to do it. That' still a pending task...

Quote:

Originally Posted by scubacat

12oz beat me to it. Especially the tensioner and idler pulleys, did you spin them by hand? Our van had a similar noise when the tensioner was on it's way out.

Both, tensioner and idler pulleys were replaced two years ago. Don't think they could be bad already and honestly I didn't spin them by hand this time, but I'll give it a try.

Scubacat, do you mean the spring inside the tensioner was worn and the tensioner was wobbly? Or just referring to the pulley?.

Oscar.

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