Engine Clack on startup

[jefo]

Hey Guys,

Recently my engine in my 89 voyager has randomly started clacking after its been sitting a while. Maybe 2 or 3 clacks on startup then it goes away immediately. What could cause this? Is the oil pump losing it's prime?

Thanks

[raccoon]

my 8 ball says its the lifters filling up. but hey as long as it goes away after a second. :)

[jefo]

Would the lifters clacking a couple of times on startup cause any damage?

[OmniLuvr]

i hate to say it, but it may also be the first signs of your rods bearings going bad, also very common, may be something you would want to look into before it gets worse, look for any signs of bearing material in the oil or oil pan. is this a turbo 2.5 or? also, what kind of mileage, ive also had problems with piston slap too. lifters seam to be more of a tic, pistons more of a clack, rods more of a knock, can be tough sometimes. with the hood open and car idling, to to give it a quick blip of the throttle, if it knocks right of idle, it could be bearings...

[minigts]

i hate to say it, but it may also be the first signs of your rods bearings going bad, also very common, may be something you would want to look into before it gets worse, look for any signs of bearing material in the oil or oil pan. is this a turbo 2.5 or? also, what kind of mileage, ive also had problems with piston slap too. lifters seam to be more of a tic, pistons more of a clack, rods more of a knock, can be tough sometimes. with the hood open and car idling, to to give it a quick blip of the throttle, if it knocks right of idle, it could be bearings...

I'm with you. Had this same problem or similar (don't know what exactly yours sounds like) and after pulling the pan and checking the bearings, they were worn down. Replaced them, replaced the oil pump and been babying the car ever since. Could be a bad seal on the oil pump too or the pump could be going out. Either way, I'd pull the pan and check things out. Unless you plan to build another motor soon, I'd order some bearings that fit and triple check the pump seal or reseal it and see if that helps.

[turbovanman²]

What oil filter? What oil? Could be the anti-drain back valve in the block has jammed open.

[zin]

All good suggestions... I'd lean towards pulling the pan for peace of mind. If it's the lash adjusters, it's not a serious problem, but if it's something in the bottom end, you'll want to get in front it.

Mike

[jefo]

Yea when the engine idles there is no noise, but revving it off idle it will start clacking mildly. My plan to pull the pan to refresh the oiling system (all new orings/ rtv sealant and new regulator spring along with cleaning the antidrainabck valve in the block. And now replace the rod bearings. Can I just buy new ones that are the factory size and swap them in? What about replacing the bolts/nut for each rod? Anyone know if sealed power bearings are good, or should I go with mopar ones?

The noise isn't noticeable inside the car, only when I pop the hood.

It is a 2.5 turbo with 120k miles. The oil pressure has been acting weird lately. Sometimes on mild acceleration the pressure would drop but go back up when i let off the gas. The oil pressure has also taken longer to rise when I start the van. This is the factory gauge btw.

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Update: it only clacks/knocks when the engine was hot after a long drive. When its warm there is none or minimal noise.

10w-30 mobil 1 high mileage with a wix filter

[jonnymopar]

Eh, sounds like lifters to me. All of my 2.5's did it regardless of the mileage, and even my 2.0 with 158k miles has done it for quite a while.

Funny you mention about your oil pressure gauge going crazy. This is exactly what happened on a 2.5 non-turbo that I had. Sometimes, when you hit the gas, the oil pressure gauge would completely bottom out. Then, when you let off, it would go back to normal. I replaced the oil pressure sending unit and got the same results. Starting with that car, I've installed a mechanical oil pressure gauge on every car I've owned since. Cheap money to know what's going on.

[jefo]

I am going to pull the pan. I ordered new clevite 77 rod an main bearings that I will install, along with the oil system seals/ regulator spring. I will also check/clean the drainback valve in the block. Nice little refresh on a 120k engine even if it turns out to be a lifter.

I am also going to pull off the balance shaft assembly, plug the oil hole in the assembly, then reinstall without the cut chain. I'm assuming it wont need oil if the chain is cut? Should raise the oil pressure a bit.

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Update: I hooked up a manual gauge and the cold idle was around 70psi, hot idle 16psi, and max of 52psi occurred at 3k rpm to redline. It sounds like the normal and to me.

[turbovanman²]

That is great oil pressure so bearings aren't your issue. I would lean towards wrist pin noise, piston slap noise or lifters.

If its a 2.5, I WOULD NOT Remove the balance shafts, you'll regret it for a DD van, been there, got the badge. Adjust the chain, if you run out of adjustment, slot the smaller shoe.

[trannybuster]

main bearings....no doubt, as long as you dont beat on it day or night they will last quite some time. th anto drain back is worth a look, maybe a better filter they have anti drain provisions a well.

[shadow88]

a few good guesses, so how about a good audio quality video so we can keep guessing?

[trannybuster]

no guess mains......rods wouldnt stop knocking and wrist pins wouldnt suddenly stop once they got prssurized oil, because they dont ever get pressurized oil...mains. you can probably hear them on highway speeds with no load on engine....

[zin]

I'll put my vote towards mains as well...

After it was suggested, I had a flashback to the 60s Pontiac Catalina Wagon BradP owned back in the 90s, it would do the same thing... start it up, and a muffled, but very pronounced low knock would greet you for a second or so, until there was enough oil in the mains to hold the crank in place!

I don't recall how long it went like that, but it was months!

I would love to have that car now, too bad it's likely become a small fleet of Hondas now!

Mike

[jefo]

I bought some clevite 77 rod and main bearings in standard size so I can swap those in when I pull the pan. I will also be refreshing the oil pump with a new spring/seals. I'll have to get a sound recording, but I figure I am going to pull the pan for the oil pump work so I'll start down there. Are clevite bearings good for racing? I don't plan on plastigauging as everything is the stock size down there, and am planning on judt bolting the new bearings in.

[turbovanman²]

Yep, Clevites are fine. I would reuse the stock pump if its ok-take it apart, if there is no wear and no scoring, the gear is fine, reuse it. Put the MP spring in. I get 25psi at idle with 5w40 synthetic oil. I find OE pumps put out more at lower rpms than aftermarket pumps.

[trannybuster]

I doubt the pump is your issue but as already stated find/use OEM. Until you check your pump how do you know its bad? Ive found nearly all of them check out fine. It would better if you could measure the crank....dump in some Lucas oil treatment, that will help but its not the fix. Also you wont be able to change out number 5 main bearing because the oil seal retainer covers it up.

[jefo]

The pumps not bad, but I am going to refresh (take apart, clean, new seals) it and put a new spring in it to raise the max pressure above 50psi. I would do plastigauge, but is there a chance that tightening and removing the bearing caps another time would weaken the bolts? That is my only worry. And yea I will be following this: http://www.turbododge.com/forums/f4/f62/93575-how-car-bearing-change-procedure.html

[minigts]

My pump had a crack in it and I believe it led to low oil pressure and the oil not staying in line when the car sat for a day or so. Thoroughly check that pump for cracks just to be sure.

[turbovanman²]

The pumps not bad, but I am going to refresh (take apart, clean, new seals) it and put a new spring in it to raise the max pressure above 50psi. I would do plastigauge, but is there a chance that tightening and removing the bearing caps another time would weaken the bolts? That is my only worry. And yea I will be following this: http://www.turbododge.com/forums/f4/f62/93575-how-car-bearing-change-procedure.html

If your using std everything, I wouldn't worry about plastiguaging, just double check the bearings say STD.

As for weakening the bolts????????? Sorry, this isn't turbododge, lol, I've reused main bolts numerous times and numerous cars, no issues.


My pump had a crack in it and I believe it led to low oil pressure and the oil not staying in line when the car sat for a day or so. Thoroughly check that pump for cracks just to be sure.

Pics?

[minigts]

If your using std everything, I wouldn't worry about plastiguaging, just double check the bearings say STD.

As for weakening the bolts????????? Sorry, this isn't turbododge, lol, I've reused main bolts numerous times and numerous cars, no issues.



Pics?

I'll get one and post it up. It was a hair-line crack I didn't notice until after I had some issues, mainly the noisy start up. Didn't take long for it to ruin the bottom end. :\

[trannybuster]

Why mess with the pump besides checking it against FSM, your pressure will raise due to the new bearings, iirc the mains see inital pressure. I too have used my main bolts many times (four or more)......and rod bolts for that matter.

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The pumps not bad, but I am going to refresh (take apart, clean, new seals) it and put a new spring in it to raise the max pressure above 50psi. I would do plastigauge, but is there a chance that tightening and removing the bearing caps another time would weaken the bolts? That is my only worry. And yea I will be following this: http://www.turbododge.com/forums/f4/f62/93575-how-car-bearing-change-procedure.html

Okay but again you wont be able to replace the last main bearing
TD
I should mention that the rear main isn't accessable on either the early or commonblock engines without removing the trans and rear seal plate. Also, the front main on the early engines requires removal of the front seal plate which means pulling the crank pully and timing sprocket. Unless the old bearings show extreme wear (missing babbit), replacing all but the rear (commonblock) or all but the front and rear (pre commonblock) should do the trick.

[minigts]

If your using std everything, I wouldn't worry about plastiguaging, just double check the bearings say STD.

As for weakening the bolts????????? Sorry, this isn't turbododge, lol, I've reused main bolts numerous times and numerous cars, no issues.



Pics?

Here's a picture. I'm assuming the crack allowed the oil to drain back into the pan, causing it to be dry at start up. Replacing the pump solved the issue.

45421

[trannybuster]

Is that the aluminium pump? Wouldnt expect that//lucky you :thumb:

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He needs to check the anti drain back on the block as stated earlier...the boys car was crazy noisy and we changed it out and got rid of most of it, but he waited too long and later changed out short block.

[jefo]

So I am replacing the bearings. On 2 rods the bearings had a 7 and on 2 they had a 6. There was other writing on them that was all the same including 89 which shows they are original. Are these bearings different or what?

Also, How do you guys remove the upper main bearing with the thrust washer? I didn't see an oil feed hole to stick the homemade tool in...

The rod bearings actually look pretty good. The mains are definitely worn more than the rod bearings.

[PunKid]

Can you post some pictures of the bearings? I will be doing this exact same thing in my car in the next week or two and what to have something to compare it to.

Almost same symptons. A quick knock or two on start up, a little at high rpm cold and more as you get the car nice and hot.

[trannybuster]

I would guess you could tap on the flange/thrust washer..make sure not to go the wrong way..ie the tab location on the bearing. That one will probably be tight.


So I am replacing the bearings. On 2 rods the bearings had a 7 and on 2 they had a 6. There was other writing on them that was all the same including 89 which shows they are original. Are these bearings different or what?

Also, How do you guys remove the upper main bearing with the thrust washer? I didn't see an oil feed hole to stick the homemade tool in...

The rod bearings actually look pretty good. The mains are definitely worn more than the rod bearings.

[jefo]

Got all the bearings swapped. Any idea why 2 rods would have bearings with a stamped 7 on them and 2 that have a 6? they were factory bearings.

[jayspartanburg]

Did that fix your problem? Not going to hijack your thread but I'm starting a new one either today or tomorrow so anyone keeping up with this one please chime in on mine.

[shackwrrr]

Got all the bearings swapped. Any idea why 2 rods would have bearings with a stamped 7 on them and 2 that have a 6? they were factory bearings.

Month that goes with the year.

[jefo]

Got it all back together and runs nice. I'll post pics of the bearings soon. I would recommend loosening all of the accessory belts to get out main bearing #1. Also keep everything really clean. And for the middle main bearing you need a softish tool to push the bearing around without scratching anything.