Cylinder Head questions

[redroadster]

Why the head gasket ?
What is going on with the engine ? Whats compression? Cold
Burning oil ? Excessive blowby?
If the valves have any pitting , best to replace
If you do pull the head and have much carbon on pistons it would be a good time to pull the eng/ trans and re ring

Have any video of the Roadster riding around on those curvy Luxembourg roads ?

[Pierre]

Few would have guessed Luxembourg. You do have a beautiful country. I look forward to some pics of you and your car in the beautiful countryside once you are driving.
I would agree to ship to Richard. I am sure JT could list a few of the mistakes shops have made. Over shaving the head is one I have heard about. Getting another head would be difficult, so....
Good luck,
Linda

Hi Linda,

I would love them to do the head but shipping (to an other country) will be to expensive!
I must say I have good faith in the machine shop in Luxembourg, they are very well known here .
Hopefully I won't be wrong, I will let you know if everything went right .
Here are some pictures from last year ...

[Pierre]

Why the head gasket ?
What is going on with the engine ? Whats compression? Cold
Burning oil ? Excessive blowby?
If the valves have any pitting , best to replace
If you do pull the head and have much carbon on pistons it would be a good time to pull the eng/ trans and re ring

Have any video of the Roadster riding around on those curvy Luxembourg roads ?

I am not sure if it is the gasket, I did not do a compression test yet but planning to do one before I would pull the head!
There is no oil / coolant (mayonnaise) mix to see when I check the oil level or remove the oil cap.
The only indication of something being wrong I have is the I feel a slight power loss while driving and over the winter I had the roadster stand in some other place.
Every 2-3 weeks I went by to start the engine mostly during the cold days.
I let the engine run fort 5 min and when I got in higher rpm's white smoke came out of the exhaust and even from under the engin hood. The video shows it.
Yesterday I went back an started the car but no white smoke so I decided to drive the car home (30 min drive) the was no smoke an do problem but I have to say I did drive slowly not exeding 3000 rpm.

When everything is fixed again I'll make some driving videos from Luxembourg. We are very small but we have some nice roads to drive, specially in the north around the old castles.

[Pierre]

Not sure about the 2000 but It is easy to put the gasket on wrong and block a water port. At least it was for me around 50 years ago when I did it.

Until the virus came I was planning on being in Luxembourg mid May. Maybe next year. I'll be n touch.

Hi Rick,

I'll make sure to be very carefully when I put it back on !
Thanks for the advice.

Where you planning a trip all over Europe? Luxembourg can be visited in 1-2 day we are very small

[C.Costine]

Pierre, one product of combustion is water. Have you never noticed water dribbling out of the tailpipe of a car when it takes off shortly after starting? Some water will get absorbed into the oil, probably not to the mayonnaise level, but it gets driven off after a few minutes of driving once the engine gets up to operating temperature. It is well known that one of the most severe automobile driving conditions is the twice a day two mile commute, where the engine never comes up to full operating temperature. I have a forklift that was larger than what was needed for the job it did for me. It ran 2-3 times a week, but only for a few minutes which was never long enough to fully warm up the big six cylinder motor from the 55 degree ambient temperature. The oil was usually milky, but once a month it would run for an hour or better, unloading a truck and placing pallets up on storage racks, and only then would the oil clear up. Pierre, I implore you to be nice to your roadster. Consider starting her only every other winter visit, and on those visits take her for a drive, get her fully warmed up, and then run her moderately hard to get the moisture driven out.

[JT68]

From watching the vidy, something is amiss i would say. I don't think that is condensation. Could be a number of things, but nothing trivial.

You probably don't need to worry about putting the gasket on backwards. That would be nearly impossible with either a U20 or R16.. they are completely asymmetric. I'm sure the cautions were well intentioned, but that would actually be hard to do.

Cheap is the enemy of good with these cars. Suggest you find someone qualified to help and it is possible you could need another head or other engine work, just depends. Maybe give Richard and Erica a call to discuss, they are nice folks. They also might be able to recommend a shop near you. Unless this is correctly diagnosed and corrected, you may spend a lot and a ton of effort and still have the same problem.

[Linda]

Very nice pics, Pierre. We definitely would love to see you driving again on those beautiful roads thru such awesome forests.
You might gain some valuable info from Richard via the video or other pics. And he could advise on some preliminary tests like compression, and the Exhaust gas test via the radiator outlet etc, to help assess the engine. Richard could advise your shop too which they might appreciate if they have never worked on a Datsun, which could easily be true.
This is a very important stage in the process

Linda

[68DSU]

Not sure about the 2000 but It is easy to put the gasket on wrong and block a water port. At least it was for me around 50 years ago when I did it.

Until the virus came I was planning on being in Luxembourg mid May. Maybe next year. I'll be n touch.

Hi Rick,

I'll make sure to be very carefully when I put it back on !
Thanks for the advice.

Where you planning a trip all over Europe? Luxembourg can be visited in 1-2 day we are very small

The plan was spend a month to drive down the Rhine. We would veer off when we wanted. We were to spend two days in Luxembourg before flying to Italy for another month...then something went very wrong. We will try again in the future.
Stay in touch with this forum. There is someone out there who can answer every question.

[Gregs672000]

The smoke appeared to occur only on deceleration. You also mentioned that you got some white smoke from under the hood too. When you let off the gas, the throttle plates shut, the vacuum on the engine side goes way up. I'm wondering if the intake manifold gasket is leaking some coolant from the water passages there. With the high vacuum, it could pull some into the intake and act like a head gasket. Pull the plugs and look for differences between them in how they're burning. The plugs that are burning coolant will likely look different and may even smell different. If it's a head gasket that might also point to which one is compromised, but I would not conclude it's a head gasket without more diagnosis as discussed. If you're burning a little coolant from the intake that could also be why power is down slightly.
Also, take a flashlight and an inspection mirror and look under the intake manifold for signs of leaks.

[redroadster]

Yeah that has the look of burning coolant for sure
It smells like burnt coolant ? It seems to disapate like it too
Didn't overheat it last time you drove it ?

[Pierre]

The smoke appeared to occur only on deceleration. You also mentioned that you got some white smoke from under the hood too. When you let off the gas, the throttle plates shut, the vacuum on the engine side goes way up. I'm wondering if the intake manifold gasket is leaking some coolant from the water passages there. With the high vacuum, it could pull some into the intake and act like a head gasket. Pull the plugs and look for differences between them in how they're burning. The plugs that are burning coolant will likely look different and may even smell different. If it's a head gasket that might also point to which one is compromised, but I would not conclude it's a head gasket without more diagnosis as discussed. If you're burning a little coolant from the intake that could also be why power is down slightly.
Also, take a flashlight and an inspection mirror and look under the intake manifold for signs of leaks.

Hi Greg,

that's a very interesting suggestion!
I did not about the intake manifold.
I pulled the plugs and the 2 in front a little bit white on the tip and the 2 on the back are black
So I do not know what to conclude from this.
I think I will have to do a pressure test trough the radiator to see if there is a leak, but now everything is complicated with the virus and I have to find someone who as the tool.
but I am missing coolant in the radiator that's for sure, I just have to find out where it goes ...
here is the video where you sea the smoke coming out of the engine bay :

[Pierre]

Yeah that has the look of burning coolant for sure
It smells like burnt coolant ? It seems to disapate like it too
Didn't overheat it last time you drove it ?

It did not overheat the last time I drove it , at least I don't think so. I have to say my temperature gauge is not working so it's hard to say.
But 4 days ago when I drove it home there was no problem at all, but as I said I drove slowly in low rpm's.

[Linda]

When was the head last retorqued? Sometimes a retorque can stop a small leak. Check archives for info.
Linda

[Gregs672000]

So, both 1 and 2 are burning coolant from some source, either the head gasket or the intake manifold. The tell will be a compression test. That should be an easy tool to locate or borrow. Let's hope they're all within 10lbs or so of each other! If that's the case, then I'd look towards your intake manifold. The bottom nuts are hard to get tight and the washers don't always engage as well as you'd like. You'll have to pull the intake to remove the head anyway, so messing with it first is not wasted time. Check the nuts under there.
A careful retorque of the head may help too as Linda suggested. Keep poking!

[todd lorber]

If you have the head off, you may want to consider port matching the head with the intake and exhaust manifolds for better flow.