Smokes up every once and awhile

Craig

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I've started a new thread that is a continuation of a previous thread, hoping that someone will see it and help me understand a little better. I'm not a mechanic.

I have an 89' SHO since 1990 that I've tried to maintain. I got it with 10K miles on it and I've really enjoyed the car. I am 70 and a pretty conservative driver.

The smoking happens when I come to a stop going down a grade, or going around a graded turn and coming to a stop, or just coming to a stop. The smoking may happen 3 times on a 15 mile trip doing errands around my small town. Recently, and it was the first time I had seen this, it smoked up when I had to accelerate hard merging into traffic on an interstate ramp. It did not seem to bother the acceleration of the car.

In the earlier post about smoking every once in awhile. NoSlo suggested that he would take off the throttle body and ensure each of the PCV pipes are clear and a drill bit can be passed through them, likewise the same inside the TB, run a wire through the three little holes untll they are clear.

I thought I would start with this. I've been to 4 mechanics so far. None of them has had any experience with this car. The fourth mechanic, a young guy with no experience with this car and without looking at the throttle body, suggested that the PVC pipes had broken down inside. I didn't feel like he knew what he was talking about.

Would you all please help me understand the suggestion by NoSlo. A description of the job would really help me in finding a mechanic for this job.

Thanks and thanks again to all of the people who particpated in the earlier thread.
Craig in a small Kentucky town
 

zoomlater

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I recommended looking into what NoSlo wrote up in your other posting. Take a look at the diagrams he posted and look at the link below. In it, you will find pictures of the engine and how some of the rubber hoses are running to the throttle body, the valve cover, etc. There are engine pictures starting around image 180. Take a look and see if the hoses on your car engine match the pictures shown. As an alternative, you could take some pictures of your car engine where the hoses go to the throttle body and we can see if the lines are hooked up correctly.

https://www.dropbox.com/sh/moz77s4au3hfx09/AADRW1HkbOsxdK9m7ctCkz05a?dl=0&preview=IMG_0180.JPG
 

Craig

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Yes zoomlater, I am hoping to start with The suggestion by NoSlo. Would the car be running well if the hoses going into the throttle body were not correct? The problem is that from time to time the car just smokes up.

I have looked at those pictures and they have helped me quite a bit in looking at my engine. But I'm thinking that what NoSlo was talking about (below) involved taking the throttle body out which I think would also mean disconnecting the hoses connected to the throttle body, and opening the throttle body up. But I just don't have the experience to really have much of a feel for what I'm talking about.

'I would take off the throttle body and ensure each of the PCV pipes are clear and a drill bit can be passed through them, likewise the same inside the TB, run a wire through the three little holes untll they are clear.'

This car has been a daily driver for me for 31 years. At times I've had good mechanics. But I've been taken before and spent a lot of time trying to find someone.

In the response in the original thread, NoSlo said:

'Something else is going on - excessive blowby causing pressure, leaking rings burning oil, for example (somebody that not cleaning spark plug wells before removing plugs could cause...) Clogged up or mis-routed hose from the front of intake to throttle body or rusty throttle body ports.

The valve-cover-to-throttle-body hose, for example, flows into the engine normally, but on WOT, will reverse and put blowby into the intake - a better place to add an oil trap can.'.

I don't understand 'excessive blowby causing pressure' or 'rusty throttle body ports' very well. Are the rusty ports the in and out ports?

But in the seal/gasket job, discussed in the original thread, the mechanic said the rings were good, there was no oil in the spark wells, and he replaced all of the hoses going into the throttle body because one had a split in it. After he had done the cam seal and sensor, valve stem seals, spark well gaskets, and valve cover gaskets, he did a leak down test, did not like the result and felt like the valve stem seals were the likely culprit, redid those, redid the leak down test, and felt like the seals were good. And I really don't have much of a feel for what a leak down test is except what the test name suggests.

The second sentence by NoSlo above might explain the smoke up on acceleration I guess.

Just a couple of sentences about how to take the throttle body out, where the PVC pipes are (and can they collaspe), And where the 3 holes are inside the throttle body. It would help me in trying to talk and listen to mechanics and try to decide if their a good choice for the job.

I think parts for the throttle body or maybe even a new or reconditioned one will be hard to find.
 

Tim Brand

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I've started a new thread that is a continuation of a previous thread, hoping that someone will see it and help me understand a little better. I'm not a mechanic.

I have an 89' SHO since 1990 that I've tried to maintain. I got it with 10K miles on it and I've really enjoyed the car. I am 70 and a pretty conservative driver.

The smoking happens when I come to a stop going down a grade, or going around a graded turn and coming to a stop, or just coming to a stop. The smoking may happen 3 times on a 15 mile trip doing errands around my small town. Recently, and it was the first time I had seen this, it smoked up when I had to accelerate hard merging into traffic on an interstate ramp. It did not seem to bother the acceleration of the car.

In the earlier post about smoking every once in awhile. NoSlo suggested that he would take off the throttle body and ensure each of the PCV pipes are clear and a drill bit can be passed through them, likewise the same inside the TB, run a wire through the three little holes untll they are clear.

I thought I would start with this. I've been to 4 mechanics so far. None of them has had any experience with this car. The fourth mechanic, a young guy with no experience with this car and without looking at the throttle body, suggested that the PVC pipes had broken down inside. I didn't feel like he knew what he was talking about.

Would you all please help me understand the suggestion by NoSlo. A description of the job would really help me in finding a mechanic for this job.

Thanks and thanks again to all of the people who particpated in the earlier thread.
Craig in a small Kentucky town
Is it coming from under the hood, or out the exhaust? My 92 has a cam seal that leaks every once and a while and will drip down onto one of the cats and smoke some doesn't happen every time I drive it just once and a while.
 

Craig

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Its mostly blue with a little white. But I'm driving when it happens. From what I've seen, its mostly blue and blue grey.
 
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FastCAD

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What color is the smoke?....
White: coolant leak
Blue: oil leak
Black: engine running very rich.
Usually oil smoke out the exhaust points to a piston ring leak but you would detect a performance issue which he says is not present. The Yamahammer produces lots of carbon and a 30yr. old has made lots of carbon and could be fouling up the works. The '89 does have OBD1??
 

zoomlater

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Yes zoomlater, I am hoping to start with The suggestion by NoSlo. Would the car be running well if the hoses going into the throttle body were not correct? The problem is that from time to time the car just smokes up.

I have looked at those pictures and they have helped me quite a bit in looking at my engine. But I'm thinking that what NoSlo was talking about (below) involved taking the throttle body out which I think would also mean disconnecting the hoses connected to the throttle body, and opening the throttle body up. But I just don't have the experience to really have much of a feel for what I'm talking about.

'I would take off the throttle body and ensure each of the PCV pipes are clear and a drill bit can be passed through them, likewise the same inside the TB, run a wire through the three little holes untll they are clear.'

This car has been a daily driver for me for 31 years. At times I've had good mechanics. But I've been taken before and spent a lot of time trying to find someone.

In the response in the original thread, NoSlo said:

'Something else is going on - excessive blowby causing pressure, leaking rings burning oil, for example (somebody that not cleaning spark plug wells before removing plugs could cause...) Clogged up or mis-routed hose from the front of intake to throttle body or rusty throttle body ports.

The valve-cover-to-throttle-body hose, for example, flows into the engine normally, but on WOT, will reverse and put blowby into the intake - a better place to add an oil trap can.'.

I don't understand 'excessive blowby causing pressure' or 'rusty throttle body ports' very well. Are the rusty ports the in and out ports?

But in the seal/gasket job, discussed in the original thread, the mechanic said the rings were good, there was no oil in the spark wells, and he replaced all of the hoses going into the throttle body because one had a split in it. After he had done the cam seal and sensor, valve stem seals, spark well gaskets, and valve cover gaskets, he did a leak down test, did not like the result and felt like the valve stem seals were the likely culprit, redid those, redid the leak down test, and felt like the seals were good. And I really don't have much of a feel for what a leak down test is except what the test name suggests.

The second sentence by NoSlo above might explain the smoke up on acceleration I guess.

Just a couple of sentences about how to take the throttle body out, where the PVC pipes are (and can they collaspe), And where the 3 holes are inside the throttle body. It would help me in trying to talk and listen to mechanics and try to decide if their a good choice for the job.

I think parts for the throttle body or maybe even a new or reconditioned one will be hard to find.
Does the hose routing on your car match those photos. I have not tried to incorrectly route hoses (not on purpose) to see what happens.

Here are a couple of pictures to show what NoSlo was mentioning about the hose connection from the valve cover to the throttle body. The throttle body is held on by four fasteners. The pencil is located in the hole that goes the valve cover hose. You can see the first small hole in the throttle body where the pencil is located. The last picture shows the location of the other two small holes.
 

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Craig

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FastCAD, I do use premium fuel always. Because of the oil use, I usually buy the cheapest 10W 30 oil lately. I never use oil with additives. I have thought about using the oil for higher mileage cars, but have not yet.

On the carbon that you mentioned, the mechanic that did the disintegrating crank gear and seal/gasket work said the engine was very clean for a car of its age. He said there was no foriegn material or corrosion and the that the engine came apart and went back together very easy.

That same mechanic that did the above work told me that the rings were good. And after that work including the redo of the valve stem seals after the 1st leak down test, he did a 2nd leak down test and told me everything was tight. I do have an ODB1 and have used it many times, but have not used it this time because the check engine light has not come on.

zoonlater, thank you for those pictures. They are a big help in helping me visualize the inside of the throttle body. I see those 3 small holes. I wonder what roll they play. Can you see the PVC pipes in these pictures? The TB looks solid. I don't see anything that looks like it might collaspe as the young mechanic who had no experience with the car suggested.

I have an 89' SHO engine manual. I've looked at p. 118 and 119 several times, where they show the crankcase emission control system.

Something I've noticed that I had not seen before is that the oil pressure light flickers from time to time at idle and goes off when I start moving.
 
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luigisho

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Does the idle drop lower than normal idle speed? There is a correlation of rpms and oil light. If it is within normal parameters I would look at rod bearing replacement. This is normal maintenance for higher mileage standard transmission SHOs. How many miles on your car?
 

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Rubber hoses connect to various ports on the throttle body. The picture with the pencil in it is the mating hole that goes to the intake hose and then to the valve cover gasket. The tiny hole in picture 2 is the end of that mating hole with the pencil in it. The other tiny holes go to different open ports at bottom end the throttle body that will mate with a different rubber hose.
 

Craig

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Iuigisho, The car usually starts on the first crank, but sometimes I have to turn the key twice. Initially, the RPMs usually go high at the start, may dip low for a moment and then settles into a very stable idle looking at the tack.

zoomlater, where are those PVC pipes in the TB? Can they be seen in any of those 3 pictures?

Thanks again you all. This forum has helped me alot through the years.
 

zoomlater

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Iuigisho, The car usually starts on the first crank, but sometimes I have to turn the key twice. Initially, the RPMs usually go high at the start, may dip low for a moment and then settles into a very stable idle looking at the tack.

zoomlater, where are those PVC pipes in the TB? Can they be seen in any of those 3 pictures?

Thanks again you all. This forum has helped me alot through the years.
if you search for PCV (spell it out) on this forum, there are several threads that discuss this:

From Off Road SHO:

The Positive Crankcase Ventilation valve is not really a valve, more a path. It goes something like this: Crankcase gases are sealed inside the crankcase except for a hole at the back of the block at the rear main seal carrier. The carrier causes the gases to zigzag up the back of the block to a cavity with a tin top with an elbow for a 1/2" hose. Both the aluminum carrier and the tin top are "cooler" than the hot oil gases and help to condense out the oil which then drains back to the pan.

The rest is sucked into the bottom of the throttle body through that 1/2" hose and then into the even cooler intake where even more of the oil condenses out.

The front valve cover also has a shrouded vent but I believe that it acts as a fresh air make-up port untill the egine rpms go way up.

From Zak:

What is different is that there is no check valve (PCV valve) in the system. It uses the three ports on the wall in the primary throttle body to create draw on the crankcase under differing engine load conditions.

At wide open throttle some gases come back up the vent (from the front valve cover) and enter the throttle body that way.


If you look at the first picture, at the bottom of the throttle body, there are two small 90 degree connection and one large connection in the middle. The large connection is the port Off Road SHO mentions. if you look at it, the large connection is in the area where the two small holes line up in the last picture.

You can ignore the two small 90 degree connections, it allows coolant to run through the throttle body and then to the area that the IAB is mounted.
 

luigisho

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A higher idle at startup and then decreasing to normal rpms is a normal function. When does the oil light come on while running? I am asking as this can signal too much wear on rod bearings and they can spin and cause damage. If you catch it early you can swap out to keep it running. If it is excessive wear this can turn into an issue that might not be worth the cost of repair.
 

Craig

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I ran the ODB1 twice and got a 19 both times. This is the CID sensor which is the cam shaft position sensor in this car I beleve. This was replaced when the CAM seal was done. I've had this sensor go bad before and I found oil in the sensor before the cam seal was done. In both cases, it really impacts the way the car runs. But the car is starting and running pretty well.

The car has about 165K miles on it. The oil light just flickers a little when the car is idling. When I just gas or accelerate even a little, It goes off.

zoomlater, I see the the 3 small holes on the circular wall of the throttle body with 2 on one side and 1 on the other side of that black rod. But what I'm seeing is confusing me.

And I may be off on my terminology here. The first picture has the 2 throttle body parts that mate up. The left part in the picture is connected to the air intake and picture 2 shows the bottom of the left image in picture 1 and is the opening that the air intake connects to. The right image in picture 1 is the part of the throttle body that connects to the manifold.

But I think the left image of picture 1 is the same as picture 3 and the pictures look like they are oriented in the same way, but the left image in the first picture shows 1 hole and the 3rd picture shows 2 small holes on the wall.

And zoomlater, I'm having trouble seeing this statement:

'If you look at the first picture, at the bottom of the throttle body, there are two small 90 degree connection and one large connection in the middle. The large connection is the port Off Road SHO mentions. if you look at it, the large connection is in the area where the two small holes line up in the last picture.'

I see the a lot of holes on the left image of picture one on the interface that mates up to the image on the right of picture 1, some of which are for the connecting bolts and there is the one with the pencil in it. And I see the 1 small hole on the left image on the circular wall. And the one bigger hole on the right image of picture 1 on the mating interface looks like it lines up with a similar hole on the left image. And I do see other holes on the mating surface of the left image of picture 1.

Please be patient with me. I know this takes a lot of time to explain. I'm trying to understand. I did think that this car has no PVC valve from looking at the maintenance schedule. From what NoSlo said, there are 4 PVC pipes. Are these shown in these pictures.
 
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zoomlater

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And I may be off on my terminology here. The first picture has the 2 throttle body parts that mate up. The left part in the picture is connected to the air intake and picture 2 shows the bottom of the left image in picture 1 and is the opening that the air intake connects to. The right image in picture 1 is the part of the throttle body that connects to the manifold.

Your observation is correct

But I think the left image of picture 1 is the same as picture 3 and the pictures look like they are oriented in the same way, but the left image in the first picture shows 1 hole and the 3rd picture shows 2 small holes on the wall.

It is the same view in the picture 1 and 3, however in picture 3, I am rotating the throttle plate (the circular plate attached to the black rod) so you can see the second tiny hole that is not visible in picture 1. When the throttle plate is closed, the second tiny hole is on the other side of the throttle plate.

And zoomlater, I'm having trouble seeing this statement:

'If you look at the first picture, at the bottom of the throttle body, there are two small 90 degree connection and one large connection in the middle. The large connection is the port Off Road SHO mentions. if you look at it, the large connection is in the area where the two small holes line up in the last picture.'

I see the a lot of holes on the left image of picture one on the interface that mates up to the image on the right of picture 1, some of which are for the connecting bolts and there is the one with the pencil in it. And I see the 1 small hole on the left image on the circular wall. And the one bigger hole on the right image of picture 1 on the mating interface looks like it lines up with a similar hole on the left image. And I do see other holes on the mating surface of the left image of picture 1.

The connections I am talking about is where three rubber hoses will connect to the three different n i p p l e s. Its at the bottom of the throttle body. I am not referring to any holes on the mating surfaces. Two of the small n i p p l e s are dirty and corroded and the big one in the middle is clean and shiny. The opening is pointed toward the main intake with the snakes.

Please be patient with me. I know this takes a lot of time to explain. I'm trying to understand. I did think that this car has no PVC valve from looking at the maintenance schedule. From what NoSlo said, there are 4 PVC pipes. Are these shown in these pictures.

I don't mind, explaining things over a chat forum is sometimes difficult. I don't think the cleaning the PCV is part of the maintenance schedule. The location of the three tiny holes corresponds to what Zak and Off Road SHO talks about in their explanations. When the throttle plate is closed, only one tiny hole is exposed to the intake. When the throttle is part open, the second tiny hole is exposed. At wide open throttle, the last tiny hole is exposed (and this tiny hole is the one that flows to the connection on the front valve cover).
 
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