I have a 97 F150 that I converted from a 4.6 to a 5.4. The 5.4 had 50k miles on it. I have a problem with the RH timing chain slapping. I have changed the chain guides,tensioner twice, all lifters on RH side. I checked oil gallies for being pluged. The one thing I have not done is change oil pump. Any ideas why the chain tensioner will not stay pumped up?

 

Yes I will bet that if you remove that chain tensioner you will find a allen plug installed in the tensioner oil supply hole of the cyl head (hole in the cyl head right behind the tensioner) Have seen this many times especially when a cyl head has been changed. People don't realize there is not suppose to be a plug installed in that hole....

 

I checked the oil supply. In fact I ran a wire in the hole to see if it would go up to the channel from the lash adjuster oil galley. I even removed the lash adjuster and pumped oil through the oil channel and had oil run out the oil supply hole for the chain tensinor. I did notice a drilled hole in the head next to the first valve spring and it goes into the oil galley. Does the hole need to have a plug in it? Or is this a drain hole for the lash adjuster oil galley?

 

The drilled hole you are talking about is suppose to be there. So you are positive that the chain tensioner can receive pressurized oil? You did remove the tensioner plunger shipping retainer clip after you installed it? You are positive the tensioner is a good one? Run a wire into the tensioner oil supply hole but this time force the wire down into the hole that is drilled downward.If the wire goes through then the plug is missing. There should be a plug in that hole that is installed from the bottom. If that plug is missing you will get oil to the tensioner but the oil pressure will direct the oil out the bottom hole and into the oilpan so you will not achieve enough oil pressure to operate the tensioner.

 

Before we continue this curret thread I think I should tell you the history of this engine. It is a 5.4 from a 2000 F150 with 50k miles on it. I was told that it had a crankshaft knock. I removed the front chain cover and the oil pan. I removed half of the main bear caps and inspected the bearings. They all had very little wear and no sign of crankshaft being out of round. I pulled half the rod bearing caps and they looked like the main bearings, smooth and even wear. I did find the RH timing chain top guide broken. I replaced the all the chains,quides,crankshaft gears, and both tensioners. I bought this timing set from Auto Zone. The chain tensioners were made from bakealite plastic not cast iron like the OEM. I built-up the engine and installed it in place of my 4.6 with 208Kmiles on it. From the first start I had a tapping noise like a collapsed lash adjuster. After putting 4K miles on the engine I replaced all the RH lash adjusters cause thats the side the noise was coming from. I put another 6K miles on the engine and the tapping noise stayed the same, not getting any better or worse. The engine sounds like a disel engine idling. Januray I removed both cam covers and checked the lash adjusters. I did not find any soft adjusters or loose cam fallowers. I happen to notice that as I turned the crankshaft the RH timing chain would go slack and then snap tight making clicking noise. I removed the front cover and watched the chains as I rotated the crankshaft. About half a turn of the crank the chain would go slack and the tensioner would compress. I could compress the chain tensioner by pushing down of chain guide. I figued the tensioner was shot. I replaced the tensioner with a cast iron one. I filled the tesioner with oil before installing it. I did remove the shipping pin and checked the front of the head for any open holes or missing plugs. I removed the front lash adjuster and pumped oil down in the oil channel. I could pump the tensioner by pushing on chain guide bleeding air out of piston. This brings us up to the first posting. I have since built-up the engine and started the engine. The engine runs very bad right now. I had fault code P1704 (lean on bank 2). The truck has sit out for two months because of cold weather. I don't have a garage to work in just a cover car port. But anyway I have changed the mass air flow sensor three times,two used,last one rebuilt. The engine runs very rough at idle and will die once it warms up. I disconnected the mass air fow connector and the runs the same. I have lost of power and some times no trottle response at lower rpm. At low driving speeds you can fill it bucking, it will smooth out at about 80 and tech above 34k rpm. Slow down to stop the idle will start hunting and drop off and die. For this I plan on pulling all injectors and flushing them, remove upper pleum and check Idle solnoid and air passages. If that don't fix anything than I'll pull it back down and start over. Sorry I got to rambling on. If you have any other toughts on trouble shooting this I'll be gratefull

 

Thanks for the history that helps. I think at this point I would perform a compression test..is it possible that somehow during this repair the engine was placed out of time and is now causing a driveability problem? I think the chain tensioner is the source of your noise but feel that during the repair the chain may have slipped and allowed a timing issue. If the lash adjusters are maintaining a solid pump then you are getting enough cyl head oil pressure. There has to be something plugged or that bottom plug is missing in the cyl head to allow bleed off and prevent oil/pressure from keeping that tensioner pumped. Since you tried different tensioners it has to be a oil supply problem to that tensioner. Is it possible that the previous owner changed that passenger side cyl head if so I have seen many times where the mechanic forgot to install one or two of the small oil passage plugs allowing a oil pressure bleed off. this can happen behind the front cover and no outside leak will be noticed.

 

Thanks for the reply. I'll do a compression test tommrow. I do have access to another set of heads for a $100 bucks. Might be good idea to buy them and have for spares. And I think I'll plan on tearing it back down after compressor test. Thanks alot. God jet engines are so much easier to work on.

 

Just a thought..With the timing chain flopping around did you notice if the chain guide pad was chewed up from the chain? If it was its possible that the pad debris has partially blocked the oil pan pickup tube sump screen and is restricting oil flow to the oil pump. Make sure to check it out using a borescope or some other means of viewing it. It can happen easily and can even fail an engine. good luck