# engine troubles



## willie (Mar 12, 2006)

I have a 1986 winnebago chieftan with 29K miles on it. However the engine makes a noise which sounds like the lifter. Anyone know how much it is to repair this or worst case what does a new Chevy 454 go for?


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## C Nash (Mar 13, 2006)

engine troubles

Willie does the engine make this noise all the time? Have you changed the oil? What kind of oil do you use? Any work be done with the air filter off and maybe let something get into the piston chamber? A lot of times 30 weight oil would cure lifter collapsing on these engine.  Might try a oil additive.  I had good results in these years with the old trusted marvel Mystery oil.  Get a broom handle and probe around the engine with one end in your ear to see if you can pinpoint the source or area.  More info will help.  Get several opinions. How long have you owned the unit?


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## willie (Mar 13, 2006)

engine troubles

It does make the noise all the time, however when you first start it up and the choke comes on you can't hear it as much because the engine is much louder.  It is most noticable at idle and taking off from a stop.  It has been making this noise for quite a while now (at least 7500 miles I would guess). It was my grandfathers Winnebago, which he bought new in 1986 and he only used it a few times each summer on average.  I think he used 10W-40 or 15W-40 oil. I have never tried Mystery oil but that is a good idea. I haven't changed the oil yet this year but in the past that hasn't seemed to cure it. Am I taking a risk driving this the way it is? It runs just fine other than the noise. Thanks for the help C Nash.


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## JimE (Mar 14, 2006)

engine troubles

Willie, I have a 1993 Winnebago with a 454 as well and I had the exact same problem.  I tried putting lloyds addative and it didn't help.  I brought it to a mechanic who replaced the knock (sp) sensor and that did the trick. It was pretty inexpensive compared to what I was prepared to pay when I thought it was a lifter tapping.


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## willie (Mar 14, 2006)

engine troubles

That is encouraging news. I will have that sensor looked at. Thanks for the feedback, I will take all suggestions into account.


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## C Nash (Mar 14, 2006)

engine troubles

Willie, I don't think your 86 has the knock sensor but memory falls me so ck on it. You may just have a lifter that needs adjusting if it makes the noise all the time. Straight 30 weight with the lucas additive worked well. Does the engine skip? Valve spring or a wore cam lobe will also give a rattle or knock.


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## pep65 (Mar 15, 2006)

engine troubles

quote:_Originally posted by willie_

I have a 1986 winnebago chieftan with 29K miles on it. However the engine makes a noise which sounds like the lifter. Anyone know how much it is to repair this or worst case what does a new Chevy 454 go for?


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## pep65 (Mar 15, 2006)

engine troubles

check for a exhaust leak where the exhaust manifold attaches to the heads and or a cracked exhaust manifold or if this engine has a heat riser they will sometimes blow a gasket and all of these can sound like a lifter going south.


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## willie (Mar 15, 2006)

engine troubles

The engine does misfire on hills and under heavy load while running on the auxillary fuel tank sometimes but it doesn't do it on the main tank.  I spoke to someone in service at a Winnebago dealer and they told me that an exhaust manifold leak is a common problem on those engines. But it doesn't really sound like an exhaust leak to me. I bought some Mystery Oil today and I am going to try that first.


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## C Nash (Mar 15, 2006)

engine troubles

Willie use a short length of heater hose and probe around the exhaust while listening in the other end for exhaust leaks. Those manifolds were notorious for cracking. Ck into valve lash adjustment.  Any mechanic should be able to just listen and determin if it is a lifter.


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## smity1373 (Mar 27, 2006)

engine troubles

I have had two 454s on two different motorhomes.  I would check for exhaust leaks first, as was said, they are notorious for this.  Pasanger side rear would be my first site to inspect. I would also get under the vehicle while it is running and listen right by the bell housing.  Sometimes a torgue converter bolt comes loose and starts to hit the housing and it might sound like a lifter.  This is an easy fix.


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