Cylinder Head only or Do both Heads and Block?

[algtrader]

I just took home a 1966 Pontiac Lemans two weeks ago and getting familiarized with the car.

The valve cover was leaking so I took it off to replace the gasket. Upon inspection, the rockers had a lot of oil crud - the type you don't want to see.

So I took off the heads and found some of the water ports clogged. I drilled out the blocked ports and cleaned them out. Both on the head and the block. After clean them out with compressed air.

The question is: Is this the right time to do a valve job on the head? A friend of mine told me if you refresh the head, it may result in more improved, higher compression and the block may start smoking oil. Is that theory correct? He said I should do both heads and engine block at the same time to do it right. This is a $3,500 job!

Meanwhile I just plan to put back the head since now I've seen what I'm dealing with. The heads look ok (aside from the oil crud stuff) and the pistons and walls look good.

What do you guys think?

I cleaned both heads and block with engine degreaser, air dried them and plan to tow the car to a shop to put the engine together.

While the heads are out, took the opportunity to paint the engine bulkhead and sides with Satin Black rustoleum.

See pics below



Thank you

Al

 

[EaOutlaw]

Since you have the heads off, look at the valve stems on exhaust side is there a bunch of carbon built up on them? if not.

Screw the spark plugs back in the holes and tighten them, flip the heads up side down and make them level.

Pour some water in the combustion area covering the valves and wait to see if any of the water seeps past the valves.

If water does not leak past the valves and seats the valve job will not increase compression more than it is now.

If the coolant ports in the heads were blocked off, the same may be said with the block.

I would at least remove all the freeze plugs and flush the coolant passages in the block.

and install new freeze plugs.


The gunk you described on the heads I am guessing your talking about dried up sludge?

If so the block will have its fair share of this stuff as well.

Which means you need to pull the pan and pick up clean them and reinstall them.

If you took the heads off why not put the rebuilt heads back on yourself.

With a manual and torque wrench this should be a easy job.

The timing chain should be checked and replaced if necessary.

With a new chain if your old one was worn and stretched and your rings are worn a new chain could cause a engine that didn't smoke to smoke.

You should have pulled a cylinder leak down test before removing the heads.

This would have told you what if any machine work would be necessary.

Make sure to clean the cylinder head bolt holes on the block good using a good quality bottom thread tap, and non flammable spray parts cleaner and compressed air.

Then spray the threads with some lubricant yet do not leave the lube puddled in the holes. clean excess lubricant out of the holes with cue tips or rolled up rags.

your only looking to remove debris, not metal from the threads so take your time go in with the tap some then back it out and clean the tap. repeat this over and over until the entire thread length is clean.

never force the tap to screw in, once the tap starts to get bound up with debris back it out clean the tap and continue.

This part I cannot stress enough, you do not want to wreck the threads or worse break off the tap in the block.

Some people will use a drill to do this yet I do not recommended any power tools cleaning these threads out.

 

[algtrader]

Hi EAOutLaw,

Thank you for the advice.

Yes, the gunk I described was dried up sludge. I cleaned out all the water ports on the heads and block, and left the head bolt holes alone. I did spray engine degreaser over the holes and cleaned them out with a rag, used a steam cleaner and blew compressed air inside them.

Good point about the timing chain. I was really thinking about that work but chose to defer it because my focus was to get the engine running again. Plus the timing chain can be replaced without touching the rest of the engine. I was planning to do the water pump with the timing chain.

I really like the leak test you described for the cylinder heads. Nice technique.

Regards

 

[algtrader]

Questions on Engine Block

Have a couple of questions on cleaning the engine block

1. I found 4 of the water ports clogged with black crud, my guess is rust, dirt and oil solidified in the holes. I drilled through the crud and was able to clean out the holes. When drilling I'm sure some of the stuff fell in... where did it go? Should I be worried about that stuff? Or will it disintegrate or get caught in the filters?

2. I also found the car had a wrong oil dipstick in it. It was for a Ford so I bought a new dipstick from OPGI. The dipstick comes in two sizes, one for a car with A/C and without. My car has A/C so I bought that one. But the dipstick is too long, since it springs out when I put it all the way in. How do I figure out what the correct oil dipstick is for the car?

Thanks.

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[melsg5]

do you have the upper dipstick tube installed which is required with AC?
i would pour a thin oil down the hole to get everything in the pan and then drain it but ideally it sounds like the whole engine should be disassembled and sent out for work. You can either pay for it now or perhaps do damage and than pay more later.

 

[EaOutlaw]

Many years ago I got a TA really cheap because of a oil light was on and it was pushing oil out many of the seals.

I drained out over 5 gallons of oil !!

whom ever built the motor left out the lower dipstick tube which directs the stick away from the crank shaft.

The crank ate the dip stick. the owner didn't know better and kept pouring oil in the engine until it touched the ate up dip stick.

After I installed the correct dip stick pieces and changed a few seals I had a great 1978 TA.

my point is like melsg5 mentioned you need a correct dipstick and you should consider taking the engine completely apart and stripping it down.

All the oil passages should be cleaned along with the coolant passages.

Machine shops have the best equipment to do this.

You will either pay now or pay more later.

That is your choice.

 

[algtrader]

Quick Update

Many years ago I got a TA really cheap because of a oil light was on and it was pushing oil out many of the seals.

I drained out over 5 gallons of oil !!

whom ever built the motor left out the lower dipstick tube which directs the stick away from the crank shaft.

The crank ate the dip stick. the owner didn't know better and kept pouring oil in the engine until it touched the ate up dip stick.

After I installed the correct dip stick pieces and changed a few seals I had a great 1978 TA.

my point is like melsg5 mentioned you need a correct dipstick and you should consider taking the engine completely apart and stripping it down.

All the oil passages should be cleaned along with the coolant passages.

Machine shops have the best equipment to do this.

You will either pay now or pay more later.

That is your choice.

Thanks for the excellent replies to my post. My respect for you guys who have been working on cars for a while has quadrupled tremendously. Watching the shows on TV they make it look so easy but when you're the one doing it, especially if you are budgeting your expenses it makes it quite difficult.

So here's a quick update on my 1966 Pontiac Lemans project

The mechanic was able to put back the top end of the engine (cylinder heads, rockers, new lifters, pushrods, intake manifold, new 4 barrel carb) and says she's purring like a kitten.

Here's a pic

However it was found upon completion of top end reassembly, that the timing/water pump housing area leaks coolant. He said the timing/water pump housing must come off to diagnose extend of leak and timing chain condition, and that for a '66 Pontiac Lemans this is a big production.

Is that correct? Is this truly a big production for this vehicle? What is it in the timing/water pump housing area that will leak coolant into the engine?

What other surprises are in store for me if I go ahead and authorize that repair? Correct me if I'm wrong but it seems I have no other choice but to have it worked on? I'm not even sure if trying to keep the matching engine numbers is worth it since this car is not a GTO.

I've already spent approx $1,500 for labor and misc parts to have the top end installed and a possible $1,200 to fix the timing chain/water pump coolant leak.

As always could use your valuable advice.

Thank you
Al
'66 Pontiac Lemans restore

 

[EaOutlaw]

I am not sure why he could not tell you the exact source of the leak.

If a Pontiac engine was any easier to work on it would be a lawnmower engine.

Do you have the car currently? or does the mechanic have it?

Is the picture representative of the engines current condition?

You do not need to take the cover off to inspect the condition of the timing chain.

to check the chain someone just needs rotate the engine over the normal direction of rotation until the timing marks line up at 0 degrees TDC for number one cylinder on compression stroke. then remove the distributor cap. once the cap is removed the rotor button should be pointing toward number one cylinder ( or close to it because of the pre set timing )

A mark should be made where the rotor is pointing to exactly on the distributor body.

then slowly rotate the engine in reverse rotation watching the rotor button when just starts to move stop the rotating the engine.

The timing marks will indicate how much slop is in the timing chain.

With this information you can decide if you want to replace the timing chain.

Anything more than 4-6 degrees slop I would change it especially if I had to do a water pump or timing chain cover.

The link below shows what all in involved with the timing chain cover.

I can only think of a few things that may cause a coolant leak, each leak should be able to be pin pointed with a coolant system pressure test.

The exception to this is if the timing chain cover gasket to block leaks coolant into the timing chain area this would be impossible to see yet coolant would leak into the engine turning your oil into a mess. same goes with the timing chain cover if it is corroded through it could leak into the engine as well.

None of the above work is hard to do, especially once you consider the price they are charging.

For $1200 you could buy a manual. and every part on the front of the engine could be replaced with new parts including a new oil pan.

I am willing to bet you could also buy all the tools you needed to do the job with and still have money left.


http://www.tpocr.com/68-75tcvrpmpipc.html


The key is a good manual. taking the time to read it and asking questions about the information you do not understand.

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[melsg5]

I agree with above, it is a little vague. Is the leak where the water pump attaches to the timing chain cover or is the leak between the cover and the block?
I also am puzzled about the picture. Is that a PCV valve in the drivers side valve cover? Is that just the picture or is there a hose connected to the passenger side oil filler cap? In the picture to the left of the thermostat housing there is a cutout in the intake and a hose is going down through it, is there a PCV installed at the end of that hose? I would never use a plastic or glass fuel filter.

 

[algtrader]

I agree with above, it is a little vague. Is the leak where the water pump attaches to the timing chain cover or is the leak between the cover and the block?
I also am puzzled about the picture. Is that a PCV valve in the drivers side valve cover? Is that just the picture or is there a hose connected to the passenger side oil filler cap? In the picture to the left of the thermostat housing there is a cutout in the intake and a hose is going down through it, is there a PCV installed at the end of that hose? I would never use a plastic or glass fuel filter.

The pic is representative of the engine's current condition. The car is in the mechanic shop. According to the mechanic he is confident the leak is between the cover and the block.

I'm curious... how would a coolant pressure test identify the source of the leak? How would you troubleshoot the source of the leak?

Since some of the coolant is now in the engine oil, I should not run the engine again, correct?

Yes, that is a PCV valve on the driver side valve cover. Yes there is a hose connected to the oil filler cap on the passenger side valve cover. And yes there is a PCV connected to the hose to the left of the thermostat housing. The mechanic's explanation was this is a CA car, these things had to do with emissions....

Anyways my gut is telling me that this mechanic may not be the right one - everything is a big production to him. Removing and inspecting the oil pan, removing the timing chain housing cover, finding a problem with the harmonic balancer, etc. I know come to realize after working with 2 classic car mechanics that "restorers" tend to be perfectionists - I say this in a good way, I sense they want to replace everything if possible. This mechanic wants me to do the whole engine and then re-seal the transmission while he's at it.

While intentions are good, I think mechanics should also consider what the client wants them to do.

My quandary right now is whether to solve the coolant leak or follow the recommendation of overhauling the entire engine to get it over with.

 

[melsg5]

A pressure test would identify an external leak. If I clearly understand what you did is removed the cylinder heads without sending them out to be checked and reinstalled them. This thread started out as sounding like you were doing all the work and now there is a mechanic involved. I would question whether the head gaskets are leaking because I assume you never had the heads checked to see if they were level? The explanation for two PCV's doesnt make much sense to me. The drivers side valve cover should have a breather but I'm unclear where that hose on the passenger side cover is going.

 

[algtrader]

A pressure test would identify an external leak. If I clearly understand what you did is removed the cylinder heads without sending them out to be checked and reinstalled them. This thread started out as sounding like you were doing all the work and now there is a mechanic involved. I would question whether the head gaskets are leaking because I assume you never had the heads checked to see if they were level? The explanation for two PCV's doesnt make much sense to me. The drivers side valve cover should have a breather but I'm unclear where that hose on the passenger side cover is going.

Hi Melsg5,

Regarding the cylinder heads: I took the heads to the machine shop and had them checked. The owner looked at them and was honest to tell me they looked fine to him.

I was doing the work but my confidence waned as everytime I did something another can of worms opened up. Felt it was time to involve a professional mechanic.

What I will do is repeat a compression test to answer my question about rebuilding the engine. If it passes, I should just address the timing cover leak and that should take care of that issue.

Thanks for the support as always

Al

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[EaOutlaw]

Hi Al,

It sounds like you have a bit of a mess on your hands.

To avoid wasting more money on this you need to consider doing the work yourself.

No one will do the right thing for you , they all will do the right thing for their wallet.

A few things have me worried, a machine shop will normally magnaflux the dissembled cylinder heads looking for cracks, they will check the surface of the head to make sure it is not warped or need machining. and they will do a 3 angle valve job replacing the valve seals and guides if needed plus any valves and springs that may be worn.

In my opinion no machinist technician or mechanic can just look at a heads and say its good.

As far as I understand you didn't have a coolant leak to start with, so why out of the blue would a leak develop from the timing chain cover. ( seems very unlikely )

If this leak started after the heads were installed my guess is the heads are warped or cracked, or the wrong head gaskets were used.

Since Pontiac made so many versions of their V8 It would not shock me that the wrong gaskets were possibly used.

My point is it is time to make lemonade out of the bunch of lemons in your hands.

My gut feeling is the work you did not feel comfortable doing yourself was not done properly by someone else.

If I had the car to repair and I wanted it done right this is what I would do.

Drain the coolant leaving the coolant out for now, change the oil and filter. then pull a compression test.

I would also have a oil pressure tester gauge installed while doing the compression test.

If the compression and oil pressure is good then, I would remove the heads, the timing cover and oil pan.

I would look at all the connecting rod caps and main bearing caps and look for signs of one or more have been overheated. any of the caps that look suspicious, ( darker than the others ) would get pulled and the bearings would be inspected.

If the bearings were good I would reinstall them torquing them to factory specs.

Then I would send the heads out to have them rebuilt.

and reinstall the heads with the proper gaskets. Normally the old gaskets are used to determine you have the correct gaskets.

Without them you you will need to pay close attention to the gaskets making sure they are for your engine and look at all the oil and water passages making sure they line up perfectly.

To make sure you get the correct gaskets have the machine shop supply you with the gaskets this way they can get the valve seals from the kit.

Your car should only have one PCV valve regardless what state is from.

As far as what goes where get the factory service manual for your car, it will show you what goes where.

I would suggest documenting everything you do with a video camera.

If you find the wrong gaskets were used and the shop provided them for you or you provided the wrong gaskets, either way the shop should have never installed the wrong gaskets.

It may be worth having proof they messed up and asking for a refund. or take it up with your bank or credit card company.

To do this you will need a manual, feel free to ask any questions were will be glad to help you through this.

I am positive that you can handle this, can of worms and all.

 

[algtrader]

EAOutlaw and Melsg5

As always good advice. Thanks.

Regarding the oil filler cap, looks like there are several configurations for the Pontiac Lemans engine.

See pics



Looks like there is a PCV at the base of the carburator and intake manifold.



This is the service manual I am using. Unfortunately it is a low quality reproduction of the original Pontiac Chassis manual. The pictures are very poor.



the poor man's manual you sent - is that the one you are using?

Thanks

 

[EaOutlaw]

For engine work a Chiltons or haynes manual should be fine.

All of my cars that I use manuals for are modern enough to be in Alldata diy I am pretty sure you car may be too old.

If you can source an original factory service manual that would be best.

the PCV valve normally goes into the valley pan a breather from the air cleaner goes to one valve cover if you have the oil cap with a tube sticking out of it make sure the foam is in place on the air cleaner housing. the foam will accumulate oil

This vent line does not come from the carburetor and a PCV valve does not get plugged into the valve cover.

My guess is the oil cap that was put on the car or the valve covers are not original.

Once you get a factory manual it will clear this up for you.

 

[melsg5]

your pictures of the 6 cylinder PCV system are of no value to you, those would be the first and last diagram from the manual. The only difference between the V8 Federal system and the California system is the Federal system pulls fresh air in through a ventilated oil filler cap and the California system has a sealed oil filler cap with a pipe on the opposite valve cover going to the air cleaner. Both systems use one PCV. So the question is what air cleaner assembly is on your car? The other question is are you registering this car in California, if not just use the Federal system. You also should look for a local Pontiac car club. They could direct you to shops that really know cars of this vintage rather than one that sticks two PCV valves on your car.

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[algtrader]

EaOutLaw and melsg5

Guys thank you very much.

I just returned that very bad reproduction of the Pontiac Tempest manual and will get a Chilton's.

Excellent idea on trying to find a local Pontiac car club. Didn't even think about that.