# Timing Chain Rattle on Start Up When Cold



## twilsey (Dec 17, 2009)

As the title suggests,

93 Nissan Hard Body, 2.4L, Manual, 2WD, 170,000 mi.

I'm experiencing timing chain rattle/slack on start up in the cold. After performing a search on this site and reading up a bit, sounds like I'm not the only one who has experienced this problem.

I learned that I have a hydraulic tensioner powered by the oil pump and once the pressure gets high enough in the tensioner, the slack is absorbed. Also, read that this can be caused by plugged or gummed up oil channels to tensioner.

Question Is:

How serious is this issue if it lasts for only 3-5 seconds on start up on cold mornings, keep in mind I live in Maine Is there anyone out there who has had this symptom for years without timing chain failure?

Second, anyone had success in curing the problem by some how cleaning out the oil ports and avoid replacing timing chain and tensioner?

Thanks in advance...


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## Biscuit (Mar 5, 2005)

It sounds like to me you do in fact have some blockage in there. I would try some engine flush or a sea foam flush in the engine. Idle it for about 5-10 minutes and then perform and oil change with some 20w-50. See if that helps a little bit. Its either that or you might be having some very slight oil pump failure.


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## rogoman (Dec 16, 2004)

The problem could be the hydraulic tensioner or a worn chain guide. First thing that probably should be done is checking the oil pressure. If it's low, the tensioner will not work properly.


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## twilsey (Dec 17, 2009)

I've continued to search previous threads and read up on the chain tensioner rattle more. Checking oil pressure first sounds like sound advise, where should I tap into the system and what is an acceptable pressure at that location? I've got a book, looks like I better start reading up on checking oil pressure.

My gut feeling here is my oil pressure is satisfactory during normal operation, but takes longer than desired to come up to pressure in the first 2-5 seconds. We will see.

Another point here is it's winter and I'm without a garage at home, I'm trying to gauge how concerned I should be about the condition and if I should go through winter with the existing condition.

Has anyone had direct personal experience of full engine failure over a start up rattle like this? I would think the chain would have to start rattling all of the time before full failure is a possibility?

I'm leaning on the side that I should be aware that I have a problem developing but shouldn't expect a chance of full failure at this stage.


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## zanegrey (Dec 5, 2005)

most likely the guides have broke and the chain is rattling..


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## rogoman (Dec 16, 2004)

twilsey said:


> I've continued to search previous threads and read up on the chain tensioner rattle more. Checking oil pressure first sounds like sound advise, where should I tap into the system and what is an acceptable pressure at that location?


If the motor is a KA24, you can check the pressure very easily by installing a temporary mechanical oil pressure gauge. You would remove the oil sensor which is located next to the oil filter and install the mechanical oil pressure gauge in it's place; you may need to get an 1/8 BSPT to 1/8 NPT adapter to hook up gauge. With the engine fully warmed up, the pressure should be as follows:
idle - at least 11 psi
3000 RPM - 60 to 70 psi


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## Grug (Aug 20, 2009)

Hey there, Twilsey. I've also done quite a bit of pokin' around on the timing chain issue. Seems to be one of the few flaws on these otherwise bullet-proof trucks.

Apparently, the earlier model engines had plastic guides. Then, Nissan switched over to metal guides. Not sure of the year they switched...you might be close with a '93.

It seems, however, that the tensioner is ultimately the culprit (assuming of course that your oil presuure is adequate). The tensioner doesn't do its thing which means the chain rattles around loosely and beats the Hell outta' the guides.

My '97 Hardbody also seems to have a slight rattle on start-up. Although, I swear it seems better with the colder temperatures that have descended upon us here in Nova Scotia. Go figure.

Anyways, I'm gonna' wait until late spring / summer to dive into mine (if in fact I do anything about it all). As long as it's only for a few seconds on start-up, I'm not gonna' press the panic button.

Just my two cents, though.

Cheers!


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## twilsey (Dec 17, 2009)

Thanks for all the feed back guys! So I will first try a new oil filter, just had my oil changed a few weeks ago and I'm suspicious of the new filter the shop put in. Next I will get a hold of an oil pressure gauge and swap that in where the pressure relay currently resides to check my start and running pressures. "Grug" I'm with you on trying to get through the winter, this truck is only used in the winter and once spring comes I could open it up and replace parts at leisure.

Anyone with more personal experience on the timing chain rattle, I'm all ears!


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## twilsey (Dec 17, 2009)

This is a good read from someone else on this subject:
==============================================================

The ol' Z24 and the KA24 are two entirely differant animals. While I have seen a couple of Z24 chains fail during my time with Nissan, it was very rare.

The NAP-Z engines used two fixed guides with a tensioner foot at the bottom of the chain and the double row timing chain. The KA24E started off with a plastic, fixed timing chain guide and a metal backed "slinger" guide that was pushed by the tensioner to take up the slack in the single row chain. (The GA16i engine used in the 89-90 Sentras/Pulsars had a similar design and similar problems.)

Initially, the first of the KA24E engines were recalled and the tensioner and "slinger" guide were replaced to a modified design.

The next issue started when people started hearing chain rattle during start-up. What happens is that debris can sometimes enter the oil feed channel to the tensioner and restrict the flow and pressure. Once the engine was running, there was sufficient oil pressure to the tensioner to properly tension the chain. However, at start-up situations, the chain would remain "slack" and rattle and would eat away at the top of the fixed, plastic chain guide. In worse cases, the fixed guide would break apart so bad that the timing chain would start cutting into the back of the front cover and could cut into the coolant jacket behind the water pump! Nothing like aluminum shavings and coolant for your engine bearings!

Eventually, Nissan finally smartened up and designed a fixed guide with a metal backing. This didn't necessarily address the main problem, but did keep the fixed guide from breaking apart and making the situation worse. 1995 models and up have the updated guide. 1994 models and earlier have the plastic guides unless they have been replaced with the updated parts. The twin cam, KA24DE, also had a similar design change on the lower chain guide, but they didn't really suffer from the problems that the KA24E did. The KA24DE did suffer from the same problem of sludge build up (usually behind the timing main gear) which caused upper chain rattle, which was "fixed" by eliminating the fixed guides of the upper chain (not really fixing the problem...just the noise).

The KA24E engine would also encounter jumped timing in some cases when the guides failed and the chain slacked. This would also retard the ignition timing as the distributor ran off of the camshaft. This I would usually see on U12 Stanzas and B12 Sentras and generally one tooth seemed to retard the timing about 8 degrees. One tooth jumped, the engine would run, but have little power. More than a few teeth would often result in bent exhaust valves.

As stated, the chains actually held up pretty well. They do not have a recommended replacement interval, like timing belts. Personally, I have a 97 H-body (which came with the KA24E and new style guide). Conventional 5W30 oil was used and Nissan filters with maintainance performed by the factory schedule. I have 200,000 miles + on the engine, which has never been apart and have no chain rattles (knock on wood) so far. I highly recommend the Nissan filter (and recommend you NOT use the Fram) and keep up on the oil changes (3000-4000 miles).

If the chain is rattling for 3 to 4 seconds at startup, it is NOT normal unless the oil has just been changed or the vehicle sits for an extended period of time (several weeks). If it is rattling that long of a period, I would recommend new guides and a tensioner. When the tensioner is removed, one can see the oil port. Remove the oil filter and clear out the port by spraying brake cleaner into the tensioner port until it sprays out of the oil filter adapter. Follow that with compressed air, if available. If there is a lot of mileage on the engine, to me it would be foolish not to replace the chain and gears while the cover is off. Obviously replace the old filter and oil prior to startup. 5W30 is recommended, regardless of whether you prefer dino oil or synthetic. It is better for the tiny ports of the hydraulic lifters, which is sometimes another problem with the KA24E engine (valve tap).

===============================================================


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## twilsey (Dec 17, 2009)

I have found a way to temporarily alleviate this symptom. In the morning when I first go to start the truck up I turn the engine over 3/4 of a full cycle or so 3-4 times in a row before starting it. Basically, the idea is to get the oil pump to push oil to the tensioner without allowing the engine to start. Then when the engine does fire up, I already have some oil pressure built up. This is not a permanent fix but it should get me through until it's warm enough outside to perform a timing kit replacement. I will certainly try the Nissan OEM filter on my next oil change as well.


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## zanegrey (Dec 5, 2005)

if the chain is loose ..it is most likely eating away the back of the t-chain cover ..


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## tinworm (Aug 20, 2009)

Mines starting to do this too, exactly the same, 3-5 seconds on start up. Wheres a good place to get the parts for this? 

I see an entire kit on rockauto.com, chain, cam and crank gears, tensioner and guides for 72 bucks. Is that reasonable?


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## yellow4wdd21 (Dec 20, 2009)

I have an 86 HB with the z24i engine and it does the exact same thing every morning. Dont think ill worry about it till it starts doing it all the time im not sure if the t-chain guides were a problem on the z24 engines mine has a double row chain and i always use nissan filters and valvoline 10-30 oil i was wondering if i should switch to a heavier weight oil?


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## carldmorseii (Jan 19, 2010)

Just replaced the timing chain, tensioner, guides, and sprockets on my friends 95 hardbody. 2.4 ka24e engine. His had a 3-4 sec rattle on start-up as well. It was like that for years, to ease your mind. On the other hand though, the plastic was wore off the guide and in pieces in the oil pan. The chain was wearing a groove in the metal on the guide. 
Just a quick reply to say..You will be fine through the winter, but get it replaced in the summer. The kit was $140. Oil, coolant, and gasket maker made the total price right around $180.
Good luck


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## Grug (Aug 20, 2009)

Hey there, carldmorseii. Was the truck you worked on 2WD or 4WD? If it was 4WD, was wondering how you dealt with the oil pan. 

Did you use OEM parts?


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## CMax03 (Jan 17, 2009)

Don't worry buddy it really isn't that big of a deal!


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## twilsey (Dec 17, 2009)

carldmorseii, thanks for the reassurance. I had mentioned a couple months ago, in this thread, that I was able to prevent the rattle by cranking the engine a couple times prior to starting it. That trick has slowly become ineffective and now I get the rattle every morning for 3 -4 sec. It will be a good project for this spring. Do you know what brand kit your friend used? Looks like there are a range of options and prices.


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## carldmorseii (Jan 19, 2010)

*Reply*

No, I used a kit purchased from Napa. ( not OEM parts) It's a four wheel drive. I loosened the pan enough so I could replace the front cover, then applied a piece of new Gasket, and Gasket maker. Let it set up for 15 minutes, then tighten the bolts.


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## carldmorseii (Jan 19, 2010)

*Kind of Kit*

Twilsey.... I don't remember the name of the kit. You can order them online for cheaper then I payed. My friend said, " Ok, you can fix my truck now, but I need it back soon." Napa had it to me the next day. If your doing it in the spring, order online.


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## twilsey (Dec 17, 2009)

Alright, I haven't put more than 30 miles on the truck all summer  But now I'm starting to think about fall. I tried changing the oil filter with a Nissan brand, no dice. So I'm diving into the timing chain repair. 

I've printed out the sticky at the top of the HB forum and I'm starting to research parts, best so far is Pep Boys for $99.99. I will most probably start into this project within the next 2 weeks. Any additional suggestions before I get into this? I'm thinking about flushing the engine with Seafoam before dumping the oil.


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## twilsey (Dec 17, 2009)

Update: I'm half way through, all parts are out and cleaned and ready for assembly tomorrow! That write up on the HB Forum Sticky is priceless, I have a manual but I only glanced at it once to double check something.

Now the fun stuff, my tensioner was in about 100 pieces at the bottom of my oil pan, the right hand guide (opposite tensioner) was completely gone except for a 3 inch piece on the upper bolt. :-0 Everything else looks pretty clean, I'm going to replace the front crank oil seal while I'm in here.

My truck was a little easier than some, 2wd and no AC or Power Steering. Fingers crossed, I'll have it back together tomorrow and maybe she will even run?! ;-)


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## 95pickup (Jul 22, 2009)

I did this last summer...

Bend the chain tensior guide as much as you can...

Also when ya first crank it.. It makes a horrible noise from the lifters. It takes up to 2o minutes to go away.

Also stabbing the oil pump-distributor is a bitch...

Good luck and take your time.. Zanegrey is a great guy for help and info.


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## twilsey (Dec 17, 2009)

Follow Up:

I have Angus (that's the trucks name) all back together and no more rattle! Ultimately it was the missing right side guide which was in about a thousand pieces at the bottom of the oil pan that caused the problem, you could see where the timing chain was chewing into the timing cover right where the water pump channel runs! Though, it probably would take a couple years to actually chew through it with the rattle just at start up.

In addition to eliminating the start up rattle, the truck is also running much smoother, maybe partially related to a fresh taught timing chain but also I have a feeling my timing was not set right on 10 deg. from the 1st spark plug (#1 spark plug was sooted up when compared to the others).

The Sticky on this forum was all I needed to perform this job, with maybe a couple quick references from the shop manual. My engine did not have the horrible lifter noise to wait through for 20 minutes, pretty much normal sounding right from the first start up. :0) Also, "95pickup" your right! Stabbing the oil pump-distributor shaft was a biatch.


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## zanegrey (Dec 5, 2005)

cheese and crackers...


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## rbo1577186 (Jan 16, 2005)

twilsey said:


> I have found a way to temporarily alleviate this symptom. In the morning when I first go to start the truck up I turn the engine over 3/4 of a full cycle or so 3-4 times in a row before starting it. Basically, the idea is to get the oil pump to push oil to the tensioner without allowing the engine to start. Then when the engine does fire up, I already have some oil pressure built up. This is not a permanent fix but it should get me through until it's warm enough outside to perform a timing kit replacement. I will certainly try the Nissan OEM filter on my next oil change as well.


I also do this after every oil change.


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## CMax03 (Jan 17, 2009)

My 86.5 had that cold startup rattle for yrs and it has metal backed guides in which the old ones were still in awesome shape @ 272,000 miles, I personally think that the Rod bolts were the source of my rattling noise during the first few minutes of running, cause it's never made that noise since they were replaced with ARP units 6-7 yrs ago.....now I'm @ 341,000 miles.


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