Nissan Frontier Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I recently started looking for a good salvage engine for my 99 frontier. I had no idea they had become somewhat rare. anyone know of a good foreign car salvage in Oklahoma?...or near?
 

·
Registered
Joined
·
2,387 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #3
wow that's some site thank you. I couldn't help but notice from your profile that you have some experience working on these things. have you ever heard of these 2.4s having timing chain tensioner problems? I saw a youtube video of a guy with his 99 Altima making the same clatter mine was before it died permanently. also mine had the same broke parts in the oil pan.
 

·
Registered
Joined
·
16 Posts

looks like a pretty good writeup. fair amount of pictures. not working on a frontier but here's his opening paragraph

"Objective: I’m going to show you how to get rid of the “marble-in-tin-can” noise coming from the front of your 240sx valve cover by removing the two guides for the upper timing chain. The guides are considered unnecessary by Nissan as seen in their TSB. DO NOT REMOVE THE GUIDE FOR LOWER CHAIN. The procedure is written for a 96 S14 but should be similar for all DOHC engines"

you might take a look and see if its similar to your truck.
 

·
Registered
Joined
·
2,387 Posts
wow that's some site thank you. I couldn't help but notice from your profile that you have some experience working on these things. have you ever heard of these 2.4s having timing chain tensioner problems? I saw a youtube video of a guy with his 99 Altima making the same clatter mine was before it died permanently. also mine had the same broke parts in the oil pan.
Yes, the KA SOHC and DOHC engines, as well as the GA16i engines in the B12 Sentras, all had timing chain "slap" issues. These engines all have oil-fed chain tensioners with a spring inside to take up the slack when the engine isn't running. In the older engines, they had problems with the fixed plastic, timing chain guide breaking (primary chain on SOHC engines and lower chain on DOHC engines. They also had issues with the chain slapping the top guide on the KA24DE engines, which they "fixed" by deleting the guide. As far as the broken guides, they updated them to a metal guide with a plastic liner. Some individuals have made kits that keep the tensioner plunger from retracting to far back into body of the tensioner to help fix start-up rattle issues. All of these are just "patches" to help make the situation better, but they really don't fix the cause of the issue, which I learned when I was working on U13 Altimas back in the '90s.
The "real" problem with these engine is that sludge or debris can get into the oil-channel to the chain tensioner. This causes a restriction or blockage of the oil to the tensioner. When starting, a restriction can slow down the oil pressure build-up at the tensioner, causing the chain to have a start-up rattle due to insufficient tension on the "slinger" chain guide, which pushes against the timing chain to take the slack out of it. After a few seconds, the oil pressure at the tensioner will get up to where it's supposed to be and create enough tension on the "slinger" guide to properly tension the timing chain and causing the rattle to stop. If it's completely blocked, it can create constant lack of tension on the chain. The initial results of this (other than the rattle noise) is that the chain starts betting the top end of the fixed-position chain guide, which is why the early, all-plastic design, would break-up and fall apart. When they came out with the KA24DE, sludge could also build up in the head where the main gear bolt threads into the head (the main gear is the gear that connects the upper and lower timing chains). As sludge builds up here, it would restrict or block the oil going to the upper chain tensioner, resulting in the upper chain slapping against the upper guide, which Nissan eventually released a TSB to eliminate the guide, which eliminated the noise (while not actually fixing the problem that caused it). The only way to fix the issue was (for the upper chains) to remove the main gear and upper tensioner and clean out the sludge where the main gear bolt threads into the engine and then use carb or brake cleaner plus compressed air to blow clear the oil channel...and, for the lower chain (DOHC) or primary chain (SOHC), remove the tensioner and oil filter and then use brake or carb cleaner plus compressed air to blow out the oil channel until it blew clear out the oil filter adapter. If you didn't and replaced chains or guides, you could still have chain rattle issues even with the new parts. A better design (IMO) was the older Datsun/Nissan engines, like the L-series and Z-series, that used two, fixed guides (backed with metal) and a spring-loaded chain tensioner with a tensioner foot that applied tension to a small area of the chain between the crank gear and beginning of the chain guide. You almost never had timing chain issues with those motors, especially when they were using the double-row timing chains.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6

looks like a pretty good writeup. fair amount of pictures. not working on a frontier but here's his opening paragraph

"Objective: I’m going to show you how to get rid of the “marble-in-tin-can” noise coming from the front of your 240sx valve cover by removing the two guides for the upper timing chain. The guides are considered unnecessary by Nissan as seen in their TSB. DO NOT REMOVE THE GUIDE FOR LOWER CHAIN. The procedure is written for a 96 S14 but should be similar for all DOHC engines"

you might take a look and see if its similar to your truck.
great article. thanks
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
Yes, the KA SOHC and DOHC engines, as well as the GA16i engines in the B12 Sentras, all had timing chain "slap" issues. These engines all have oil-fed chain tensioners with a spring inside to take up the slack when the engine isn't running. In the older engines, they had problems with the fixed plastic, timing chain guide breaking (primary chain on SOHC engines and lower chain on DOHC engines. They also had issues with the chain slapping the top guide on the KA24DE engines, which they "fixed" by deleting the guide. As far as the broken guides, they updated them to a metal guide with a plastic liner. Some individuals have made kits that keep the tensioner plunger from retracting to far back into body of the tensioner to help fix start-up rattle issues. All of these are just "patches" to help make the situation better, but they really don't fix the cause of the issue, which I learned when I was working on U13 Altimas back in the '90s.
The "real" problem with these engine is that sludge or debris can get into the oil-channel to the chain tensioner. This causes a restriction or blockage of the oil to the tensioner. When starting, a restriction can slow down the oil pressure build-up at the tensioner, causing the chain to have a start-up rattle due to insufficient tension on the "slinger" chain guide, which pushes against the timing chain to take the slack out of it. After a few seconds, the oil pressure at the tensioner will get up to where it's supposed to be and create enough tension on the "slinger" guide to properly tension the timing chain and causing the rattle to stop. If it's completely blocked, it can create constant lack of tension on the chain. The initial results of this (other than the rattle noise) is that the chain starts betting the top end of the fixed-position chain guide, which is why the early, all-plastic design, would break-up and fall apart. When they came out with the KA24DE, sludge could also build up in the head where the main gear bolt threads into the head (the main gear is the gear that connects the upper and lower timing chains). As sludge builds up here, it would restrict or block the oil going to the upper chain tensioner, resulting in the upper chain slapping against the upper guide, which Nissan eventually released a TSB to eliminate the guide, which eliminated the noise (while not actually fixing the problem that caused it). The only way to fix the issue was (for the upper chains) to remove the main gear and upper tensioner and clean out the sludge where the main gear bolt threads into the engine and then use carb or brake cleaner plus compressed air to blow clear the oil channel...and, for the lower chain (DOHC) or primary chain (SOHC), remove the tensioner and oil filter and then use brake or carb cleaner plus compressed air to blow out the oil channel until it blew clear out the oil filter adapter. If you didn't and replaced chains or guides, you could still have chain rattle issues even with the new parts. A better design (IMO) was the older Datsun/Nissan engines, like the L-series and Z-series, that used two, fixed guides (backed with metal) and a spring-loaded chain tensioner with a tensioner foot that applied tension to a small area of the chain between the crank gear and beginning of the chain guide. You almost never had timing chain issues with those motors, especially when they were using the double-row timing chains.
great information. thanks
 
1 - 7 of 7 Posts
Top