BIGHVM
Explorer Addict
- Joined
- November 25, 2007
- Messages
- 1,638
- Reaction score
- 0
- City, State
- UK, Richmond, Surrrey.
- Year, Model & Trim Level
- 2000 Northface
When Ford (USA) wanted a replacement to their 4.0 OHV engine, they decided on a cam-in-head OHC design. They designated this engine the SOHC, even though it has 2 camshafts.
The camshafts are driven by chains which run in plastic guides. The problem arises when the plastic in the guides starts to break up, or the spring-steel in the 2 lower chain tensioners sets itself free. The chains then rattle against the side of the head or block and the broken pieces of plastic or steel mill aound in the engine voids. When the parts are broken in to small enough pieces, they make their way into the sump and can be drawn into the oil pickup, where the fragments settle in the strainer, causing slow build up of oil pressure and restricted oil flow.
The LH chain is scurfing the outside of the head and block, bringing metal and plastic particles up into the the cam case, where they congeal into a black mush, which eventually makes its way into the hydraulic tappets' oil reservoirs, causing sticky tappets. Meanwhile, the RH chain is slowly destroying the upper cassette retaining bolt and, on its way down, scurfing the block and depositing fine particles into the sump.
These engines may go on for many miles in this condition, the only clue being a rattle from the chains on start up, a rattle on idle, and, perhaps, the occasional fault indication on the dashboard (low oil pressure, engine management light). The rattle sounds a bit like tappets and it will come and go, and can become too loud to ignore. Ignore these warnings at your risk, because the engine is preparing to surprise you in one of the following ways...
The chain breaks through the left hand cam cover, allowing oil to spill over the exhaust manifold.
The jackshaft chain breaks through the timing cover
The valve timing slips, causing loss of power and, possibly, bent valves.
A chain breaks, causing untold damage.
Prevention would be better than cure and a check on the condition of the chains and guides, followed by appropriate remedial work, might save some expensive repair work later.
Ford (UK) made these engines the subject of a warranty extension and redesigned the timing components to provide a long lasting solution. Most Explorers in the UK slipped through the net and therefore still have the original parts fitted.
As far as I can ascertain, there is no service interval for replacing these parts, unlike most cars where the 'cam belt service interval' is well documented.
As a result, most Explorers are still running on the original equipment, which, in my opinion has a design fault.
Ford now supply a re-designed assembly, which is much more rubust and does appear to have addressed the design flaws in the original fitment.
I have seen these engines with problems at 40k miles and others which are still serviceable at 110k miles. Typically, 60000-80000 miles is the danger zone.
This is a copy and paste from an add on Ebay, I am a little upset to read that Ford made our engines a warranty extension for this problem, well how comes it seems most of us have not had this done- ok I can accept that maybe the car was not our car at the time, but if any owner would have had a call or letter about this, they would almost certainly have taken notice and had it done-yes?
Anyone have any real detail on this from customers angle, did you get notice if you had your Ex in this time frame, can you scan and post the letter here please.
I just cant see how a Global seller like Ford could let this go without contacting following owners about this issue- if they did just that, well its a very poor show and worthy of great ill feeling!
The camshafts are driven by chains which run in plastic guides. The problem arises when the plastic in the guides starts to break up, or the spring-steel in the 2 lower chain tensioners sets itself free. The chains then rattle against the side of the head or block and the broken pieces of plastic or steel mill aound in the engine voids. When the parts are broken in to small enough pieces, they make their way into the sump and can be drawn into the oil pickup, where the fragments settle in the strainer, causing slow build up of oil pressure and restricted oil flow.
The LH chain is scurfing the outside of the head and block, bringing metal and plastic particles up into the the cam case, where they congeal into a black mush, which eventually makes its way into the hydraulic tappets' oil reservoirs, causing sticky tappets. Meanwhile, the RH chain is slowly destroying the upper cassette retaining bolt and, on its way down, scurfing the block and depositing fine particles into the sump.
These engines may go on for many miles in this condition, the only clue being a rattle from the chains on start up, a rattle on idle, and, perhaps, the occasional fault indication on the dashboard (low oil pressure, engine management light). The rattle sounds a bit like tappets and it will come and go, and can become too loud to ignore. Ignore these warnings at your risk, because the engine is preparing to surprise you in one of the following ways...
The chain breaks through the left hand cam cover, allowing oil to spill over the exhaust manifold.
The jackshaft chain breaks through the timing cover
The valve timing slips, causing loss of power and, possibly, bent valves.
A chain breaks, causing untold damage.
Prevention would be better than cure and a check on the condition of the chains and guides, followed by appropriate remedial work, might save some expensive repair work later.
Ford (UK) made these engines the subject of a warranty extension and redesigned the timing components to provide a long lasting solution. Most Explorers in the UK slipped through the net and therefore still have the original parts fitted.
As far as I can ascertain, there is no service interval for replacing these parts, unlike most cars where the 'cam belt service interval' is well documented.
As a result, most Explorers are still running on the original equipment, which, in my opinion has a design fault.
Ford now supply a re-designed assembly, which is much more rubust and does appear to have addressed the design flaws in the original fitment.
I have seen these engines with problems at 40k miles and others which are still serviceable at 110k miles. Typically, 60000-80000 miles is the danger zone.
This is a copy and paste from an add on Ebay, I am a little upset to read that Ford made our engines a warranty extension for this problem, well how comes it seems most of us have not had this done- ok I can accept that maybe the car was not our car at the time, but if any owner would have had a call or letter about this, they would almost certainly have taken notice and had it done-yes?
Anyone have any real detail on this from customers angle, did you get notice if you had your Ex in this time frame, can you scan and post the letter here please.
I just cant see how a Global seller like Ford could let this go without contacting following owners about this issue- if they did just that, well its a very poor show and worthy of great ill feeling!
