2008 Explorer 4.0L SOHC Maintenance Questions

[JetTech1966]

My sister in-law owns a 2008 Explorer with the SOHC engine in it. It currently has 70K miles on it and I'm curious as to what it might need in the future. I do all of the work on it but want to keep it running perfect for her for many years to come and fortunately she has no problem paying for preventative maintenance. So my question is what should I do or have her plan for with that engine in the future? Actually my concern is mainly with the cam chain guides. Is it recommended that they be changed at 100K miles or thereabouts or are they good for the life of the engine? I just want to keep it running smooth for her and will change or do whatever you all recommend to it. Thanks for your time and for this great forum...

 

[PEAR0119]

it all depends really. Are they making noise? is there a pinging type noise under load between 2000-3000 RPM? If so I would get them serviced. I have 47K miles on mine and it is in the shop now to get the timing chains replaced because of said noises.

Regular engine oil changes is a must. Also I would recommend changing all fluids at the 100k mark (front diff, transfer case, trans, rear diff). Also, plugs and wires may not be a bad idea either. Taking the TB off and giving it a good cleaning wouldn't hurt, also cleaning the MAF wouldn't be a bad idea.

 

[2000StreetRod]

hydraulic tensioners

I suggest replacing the left and right spring/hydraulic camshaft chain tensioners every 75,000 miles. The timing chain guide surfaces that contact the chains could easily last 500,000 miles. Mine were only about 1/10th worn when I replaced them at 150,000. Unfortunately, the guides break into pieces long before wearing out. Most members experience warning sounds from the engine at the beginning of timing chain problems. I would wait until then before taking any action. See my helpful threads for more information on timing chain issues.

 

[JetTech1966]

it all depends really. Are they making noise? is there a pinging type noise under load between 2000-3000 RPM? If so I would get them serviced. I have 47K miles on mine and it is in the shop now to get the timing chains replaced because of said noises.

Regular engine oil changes is a must. Also I would recommend changing all fluids at the 100k mark (front diff, transfer case, trans, rear diff). Also, plugs and wires may not be a bad idea either. Taking the TB off and giving it a good cleaning wouldn't hurt, also cleaning the MAF wouldn't be a bad idea.

Thanks for the tips, at 100K I was going to replace all fluids, brake fluid to the rear diff. Right now the engine is quiet and running smooth thankfully. I appreciate your response.

 

[JetTech1966]

I suggest replacing the left and right spring/hydraulic camshaft chain tensioners every 75,000 miles. The timing chain guide surfaces that contact the chains could easily last 500,000 miles. Mine were only about 1/10th worn when I replaced them at 150,000. Unfortunately, the guides break into pieces long before wearing out. Most members experience warning sounds from the engine at the beginning of timing chain problems. I would wait until then before taking any action. See my helpful threads for more information on timing chain issues.

Will do sir and thank you very much!!

 

[PEAR0119]

I just got news from the dealer and they are replacing my primary timing chain tensioner. With only 47K it just goes to show that they can go at any point.

 

[PEAR0119]

I suggest replacing the left and right spring/hydraulic camshaft chain tensioners every 75,000 miles. The timing chain guide surfaces that contact the chains could easily last 500,000 miles. Mine were only about 1/10th worn when I replaced them at 150,000. Unfortunately, the guides break into pieces long before wearing out. Most members experience warning sounds from the engine at the beginning of timing chain problems. I would wait until then before taking any action. See my helpful threads for more information on timing chain issues.

Since the dealer replaced my primary timing chain tensioner, they noticed that the engine was still making noise, it ending up being the balance shaft guide and tensioner that grenaded. But now I have a rattle noise only on startup and after a prolonged rest (ex. over night) which only lasts about 2-3 seconds and then completely disappears. Would this noise be caused by weak spring/hydraulic camshaft chain tensioners? It almost seems like when there is no oil pressure in the tensioners the springs are too weak to keep proper tension on the chains.