1984 Chevy 454 smokes when warm

[ErikTande]

I have a new to me 1984 fleetwood southwind that smokes from the exhaust when it's warmed up (takes about 30 mins).     I'm going to rent a headgasket test (the kind that tests your radiator with blue/yellow fluid) and see what those results are.    I also ordered a real water temp gauge so I can know what the actual temp of the engine is.  It shouldn't be running over 220, right?

I'm new to big carbureted engines but I'm pretty handy.   I've done headgaskets on small engines before so if it comes to that I'm confident I can do it, but tips and guidance is always appreciated.  What else could it be, and what else should I be looking for? 

Thanks!!!

Here's my new rig:

[M & J]

First off, welcome to the forum.

Secondly, what color is the smoke?

[MotorPro]

White,blue or black?

[ErikTande]

White smoke, maybe blue-ish tint, I'll have to double check.   I've only driven in far enough to get it to smoke a couple times.

[wae]

What does it smell like?  If the carb isn't backing off of its warmup enrichment and is continuing to dump fuel, you might be running too rich.  I know that it's supposed to be black smoke in that case, but I've gotten a more white looking smoke from pushing my req*fuel numbers way up and forcing it to run super rich. 


White smoke is usually coolant, though, and should give off a bit of a sweet smell, assuming you have antifreeze in the system.  Have you been turning up low on coolant lately?  Any tiny green bubbles on the dipstick?


If it's grey or grey/blue you're looking at oil.  Usually that's rings or valve seals.  Can you do a leak-down test?

[Rickf1985]

I think you are headed in the right direction, let us know what the test tells you. If it comes up negative it could be valve seals. How many miles are on it?

[ErikTande]

62000 miles.  I just got it and have only driven it a couple times so I don't have a ton of info yet.   It doesn't really smell sweet, smells hot though, maybe a little like burning oil but my nose is an awful indicator : P

I can do a leak down test, I'm going to do the headgasket test today with this tool and I'll get back to you guys!

[ErikTande]

Good news! (maybe).   Head gasket seems fine, I let it run for about 5 minutes with this thing squeezing the little ball and it didn't change color. 



I'm going to install my water temp gauge next, let it warm up, see how hot it is and see what color the smoke is.

[Rickf1985]

5 minutes isn't really long enough for the engine to get good and hot. You are going to want it run at least 20 minutes to a half hour and then check for the head gasket test. Just leave the radiator cap loose. It should not boil over just sitting there, if it does then it probably is pushing combustion gas into the coolant. If you don't leave the cap loose then you will not be able to take it off when hot, it will boil over if it depressurizes quickly.

[ErikTande]

Gotcha, I let it run for 30 minutes and did the test again, still good on the head gasket test.    The smoke is blue and is really only coming out the driver side bank.   Here's a video:

https://youtu.be/26zJXa8FhAY

[Rickf1985]

Now, if you rev it up a couple times does it get real bad and then lighten up? If you are driving should be almost no smoke but when you start a puff of smoke and after idling for a while. If that is the case then it is valve seals.

[M & J]

Agreed.

[CapnDirk]

Possible RT head was repaired singularly for some odd reason and is fresher, broken ring(s).  One or more valve stem seals popped of the base, valve guide moved facilitating the seal coming off,  and I've seem people use such cheap oil it restricted the oil flowing back to the crankcase and after some time the valves and seals were under water (meaning under oil).


I would pull the valve cover and plugs.  See what the top side of the head looks like, check compression, then a leak down test (on the left side).  Good news is that with some simple tools you can change the valve stem seals with the head on the engine.  You might pull the plugs on the left side and see which one(s) are black.  Pull one at a time and look at them.  Cheap simple minimum time, and can narrow it down to a single cylinder if it is.

[tarifachris]

Buy a vacuum gauge and measure and test the manifold vacuum!!!

[Warren]

Eric  - I tried the tester.   And got mixed results.  I drove it and got it up to operating temp.   Also let it idle up to operating temp.   So after getting frustrated, I headed over to an independent repair shop,  and used the exhaust
gas analyzer.  Started at 30 PPM and ended up over 50 PPM.   Had a bad head gasket.   Retested after replacing head gaskets, resurfaced heads, etc.    Tested at 4-6PPM.       Cost for the testing?  Beer money!!

[ErikTande]

Possible RT head was repaired singularly for some odd reason and is fresher, broken ring(s).  One or more valve stem seals popped of the base, valve guide moved facilitating the seal coming off,  and I've seem people use such cheap oil it restricted the oil flowing back to the crankcase and after some time the valves and seals were under water (meaning under oil).


I would pull the valve cover and plugs.  See what the top side of the head looks like, check compression, then a leak down test (on the left side).  Good news is that with some simple tools you can change the valve stem seals with the head on the engine.  You might pull the plugs on the left side and see which one(s) are black.  Pull one at a time and look at them.  Cheap simple minimum time, and can narrow it down to a single cylinder if it is.

Thanks!  Yes, revving it or driving it seems to lessen it (although it's hard to tell when you're moving) and a bit bigger puff after idleing for a while then starting.

I'll pull the plugs and see which ones are most affected.   What tools do I need to change the valve stem seals?   Does anyone have a good link to a tutorial or video for this specific motor?   Thanks again!  I'm trying to get this thing ready for a 1000 mile drive to Hanska, MN for a family reunion in 3 weeks : D

[legomybago]

throw a set of plugs in it and take it out for a long cruise....

[M & J]

This will get you started:

https://youtu.be/ob_4-F-m1FI

Ive done it on sb chevys a few times.

[Rickf1985]

Three weeks is pushing it, I say check the oil and drive it. Tools are not bad, valve spring compressor and the adapter fitting to put compressed air in the cylinder to hold the valves closed so you don't drop a valve in the cylinder, magnet for the valve keepers and assorted sockets and ratchets for the rockers and valve covers. But if you are leaving in three weeks you have plenty of other stuff to check. How old are the tires? If more than 5 years they should be replaced due to dry rot. Brakes? Brake lines? Be sure to find and check the fuel pressure regulator, it will be somewhere on the fuel line on the passenger side back close to the tank. They are famous for leaking. And they are usually in an impossible spot to get to. Be sure to change the fuel filter that will be along the frame rail about where you side entrance door is. that is forgotten a lot and causes a lot of issues. These are just some of the normal problems we have all run into that you will want to find in your driveway and not on the side of the road.

[circleD]

FYI. The fuel filter on the frame rail is easy to get to but hard to work on. I redone my fuel lines and moved the filter to an easier access area.

[DaveVA78Chieftain]

Be sure to find and check the fuel pressure regulator, it will be somewhere on the fuel line on the passenger side back close to the tank. They are famous for leaking. And they are usually in an impossible spot to get to.

This is a 83 or 84 chassis.

Factory installed in tank Electric Fuel Pump and it's companion fuel regulator did not start until 1985 1/2.  GM did recommend that the RV owner install an External Electric Fuel Pump for chassis' prior to that.

[ErikTande]

This will get you started:

https://youtu.be/ob_4-F-m1FI

Ive done it on sb chevys a few times.

That's perfect, thanks! I can handle that no problem.    Summit has a ton of different valve stem seals listed, any idea which ones I should order?

Three weeks is pushing it, I say check the oil and drive it. Tools are not bad, valve spring compressor and the adapter fitting to put compressed air in the cylinder to hold the valves closed so you don't drop a valve in the cylinder, magnet for the valve keepers and assorted sockets and ratchets for the rockers and valve covers. But if you are leaving in three weeks you have plenty of other stuff to check. How old are the tires? If more than 5 years they should be replaced due to dry rot. Brakes? Brake lines? Be sure to find and check the fuel pressure regulator, it will be somewhere on the fuel line on the passenger side back close to the tank. They are famous for leaking. And they are usually in an impossible spot to get to. Be sure to change the fuel filter that will be along the frame rail about where you side entrance door is. that is forgotten a lot and causes a lot of issues. These are just some of the normal problems we have all run into that you will want to find in your driveway and not on the side of the road.

I put all 6 brand new tires on it already (first thing I did).  Brakes are good.   Got it aligned with the front wheel bearings repacked, made a HUGE difference in handling. 

I'll definitely do the fuel filter.   Is the fuel filter on the frame rail the only one?

Thanks!

[Rickf1985]

Good info from Dave on the rear pump. And it seems you are pretty much on top of things. There is another filter in the inlet of the carburetor, takes a one inch wrench to get the nut off. Make sure you put the new one in in the right direction or it can cause a restriction. And be real careful putting that big nut back on because they tend to cross thread in the aluminum carb housing, put it all the in by hand and then tighten it with the wrench. The one way I have found to tell if it has the rear in tank pump is if it has 1/2" fuel line coming up from the rear. No pump in the tank and it will have 3/8" line. I think with an inline pump it would still have the 3/8 line.

[CapnDirk]

Your engine will be easier than the video, less junk in the way.  A  compressor is needed, and the tools.


Possible tools:
https://jet.com/product/detail/f9acc47596f6460e8fcabb9b9e1dbdd2?jcmp=pla:ggl:NJ_dur_Gen_Tools_Home_Improvement_a2:Tools_Home_Improvement_Power_Hand_Tools_Hand_Tool_Sets_a2:na:PLA_784744689_42602105993_pla-293683380228:na:na:na:2&code=PLA15&pid=kenshoo_int&c=784744689&is_retargeting=true&clickid=a9b91948-edb8-487a-ad6e-5afb6553cb1f


And
https://www.summitracing.com/parts/pro-66784?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-proform-parts&gclid=Cj0KEQjwkN3KBRCu2fWmy9LLqN4BEiQANP9-Wo52rnuxhQZzRnf0eODz5W5g47PBxvXriohea7dcJsYaAqgD8P8HAQ


https://www.summitracing.com/parts/wmr-w84003/overview/


Some auto parts stores rent toools, but not sure they would have something like that, you might call around.

[Rickf1985]

Those valve spring compressors are all a bit of over kill! And the seals just get standard seals at any parts store. The ones from a race place that seal tight to the stem boss require machining of the that boss. A standard seal does not sit tight against the bottom, it hangs onto the valve stem and the oil drips off of it, hence the name "umbrella seals". You need some oil on the valve stem for lubrication. I will try to find a picture of a standard spring compressor, Photobucket has shut down so I cannot take pictures of mine and post them.

Here you go, plain and simple. I have been using the same one for 40 years.

https://www.amazon.com/OTC-4573-Universal-Overhead-Compressor/dp/B000F5HUUI/ref=sr_1_4?ie=UTF8&qid=1498925654&sr=8-4&keywords=valve+spring+compressor