QuestionI've had a '93 Ford Ranger XLT, 4.0 litre automatic for just over a
year now. It was propane converted when new. A few months
ago I started hearing a 'rattling' or 'ticking' sound on cold starts.
What it _sounds_ like is a frayed belt hitting against sheet metal,
but that's not it - the belt is fine. The sound definitely makes
one think that something is loose and hitting against
something it shouldn't... The sound appears to come from the
underneath, backside of the engine in the bell housing/oil pan
area. The ticking is somewhat random in nature (not a uniform
tappet sound), and increases in frequency and loudness as the
engine is reved. After a minute or so though, whether idling or
underway, the sound disappears, and doesn't come back till the
next cold start. (Occasionally I've heard it on a warm start.)
There appears to be a sensitivity to parking angle - facing uphill
or level, the noise is there; facing downhill it's less pronounced
or absent.
I'm thinking it must be heat or oil pressure related as the sound
only lasts a minute or so before disappearing. The oil is very clean
(probably because it's a propane vehicle), but I did notice some
bubbles in it when I checked the level the other day, something I
haven't noticed before in other vehicles(?) In all other respects, the
engine seems to run fine.
Any ideas of what the sound could be and whether it's the start
of a bigger issue?
AnswerHello and thanks for the question...I'll try to help.
I hate to say it, but even though it is not your uniform tappet sound, it sounds like the tappets are bleeding down.
The reason that you hear the noise more so when parked up hill is that the oil pick up screen is located towards the front of the engine---your truck being tilted rearward-the oil is in towards the rear of the oil pan.
Here is a link for Autozone.com:
http://www.autozone.com/servlet/UiBroker?UseCase=C001&UserAction=performSearch&P...
You will also need a head gasket set, bolts, and an intake gasket set.
Hope this helps,
Erik
