water pump

[islander]

been cruzen in the 510,notice water temp read 230. put in a new aluminum rad & thermostat last month & temp was never went above 190.Checked thermostat in boiling water & was opeaning.Seems like its got an air lock,cause when i look @ the water with rad cap off, instead of circulateing it just wants to boil over.it has a 2 liter instead of the 1.6. So m  wondering if the water pump is working? When they go bad do they leak ? or could the impeller have come loose on the water pump? Do not want to cook my engine,so any suggestons? M new to Datsuns.

[datzenmike]

Air lock is impossible. The thermostat is the highest point on the engine. As soon as the thermostat opens any air that may have caught behind it would escape into the top tank of the rad. If you have a 510 thermostat it has a jiggle valve that would let the air out even when closed.

 

You may very well have already 'cooked' your engine. How do you know it was at 230? Has to be an aftermarket gauge. Not much sense not keeping an eye on it. Running it that hot has very possibly blown the head gasket and warped the head. Compression is blowing out of the cylinder and into the water jacket. This will push the water ahead of it and out the open rad cap.

 

Good news is it's fixable. If you do the work yourself it's $30 for a NAPA Felpro gasket.

[islander]

yes got an aftermarket temp gauge on it. What would my next move be? a compression check? seems to run o.k. but head gasket makes sense cause when looking @ water it bubbles up with with white bubbles.Oil looks good.

[islander]

oh yea, been haveing trouble with run-on.been tring to fix but have been shut off & popping out clutch to kill it. Some thing sounding bad one time lately when shutting off, like something broke.Could this be related?

[datzenmike]

Does it bubble when first starting and running while it's still cold?

 

 

[Stoffregen Motorsports]

General rule of thumb - if it overheats with coolant in it, it's usually ok. If you run it out of coolant, you're in trouble.

 

I always cut the jiggle valve out of the thermostat, even on new modern engines. This helps bleed the system.

 

Check the temp of the gauge by running it in your driveway with the radiator cap off, and stick a thermometer in the top of the radiator. The two should read the same.

 

https://www.amazon.com/OEMTOOLS-24352-Instant-Read-Thermometer/dp/B008RLYDMU/ref=asc_df_B008RLYDMU/

[islander]

had a look this morning & the water in rad did Not bubble when first starting up or when cold. after a few minutes when engine temp got to about 180,(180 termostat) then it started to bubble up. Engine seems to run good. Did not know what a giggle valve was untill yesterday, so m learning.Thinking about putting rad cap on & going for a ride to c if temp rises above 190, What u think, Bad idea??

[datzenmike]

Could still be a blowing gasket, not completely gone yet. Idle isn't much pressure compared to driving. Also may be more pronounced when engine is warmed up.

 

If there is compression leaking into the cooling system take note of the rad hoses. If they get really hard then don't take the rad cap off without some rags over it.

[islander]

with my luck it probably is the head gasket.Something seems not right & there must have been a reason the temp went real high in the first place, druring our heat wave afew weeks ago it did not go over 190. Do u think this could have been caused by run on & popping the cluch ? Should i do a compession check? What would u do next,cause i really do value your opion & will listen & do. Thanks.

[datzenmike]

If 150 PSI compression gets into the cooling system it will easily over power the 13 PSI rad cap and push the coolant out the overflow pipe and you may never even notice it. It may slowly lower the coolant level in the rad till it over heats. Could take weeks or days or just a few minutes. When was the last time previous to this that you checked the rad level? Once a week is more than enough and noticing sudden unexplained coolant loss would suggest that you find out the cause. 

 

Near where on the Island are you?

[islander]

M just off 17th street,your town. Will make sure m around if u happen to passing by. Dont spend much time on inter-net, but can text @ 250-702-3500.

[datzenmike]

Sounds right. Big garage in the back alley? I walked through there Monday on way home to see if there was a Datsun showing. No luck, must be inside.

[islander]

yea, think u got the right place. keep the 510 in the garage. It sounds like you r discribeing my overheating issue to a T. M pretty sure u r right about the head gasket but just want to make sure before i start takeing it apart. Have not done a head gasket before, but think i can.

[datzenmike]

STOP!!!!!!

 

Before going any farther you have to know before you start, that the timing chain has a tensioner. If it isn't properly secured before hand it will pop out of it's holder when the cam sprocket is loosened. Once out, the entire front of the engine must come off to get it back in. This must be avoided at all costs or at least another 3-4 hours work and more gaskets and a crank seal will be needed.

 

Are you home in the early afternoon? I can drop by and shoot the shit about it. Haven't seen a 510 in years, would love to see it..

 

 

[islander]

well its to the parts store we go for a head gasket. Lucky enough to have Datzen Mike watching my back. 🙂

[banzai510(hainz)]

you sure its the head gasket??????????????

[islander]

had Datzen Mike look @ it & yea it seems to b leaking compression in to the cooling sytem.

[datzenmike]

6 hours ago, banzai510(hainz) said:

you sure its the head gasket??????????????

 

Opened the rad cap then tightened it back on. Started the engine when cold. Gave a few sharp revs and shut off. Loosened rad cap slowly with ear near it and it hissed. Thought it was done so loosened it fully and it puffed out. Earlier I took the rad cap off and could smell gas and my sniffer is really old.

[datzenmike]

While not definitive plugs 1 and 4 were clean and tan, 3 and 4 were fouled. I suspect the gasket is slightly blown between 3 and 4 and the compression seesaws back and forth. 

 

Has a header so the manifolds need to come off, was going to lift head with manifolds on to save fucking up a stud and replacing a good gasket. So $20 for manifold gasket and about $30 for the HG. I have a commercial straight edge for checking warpage.

 

BTW islander here's the U67 head I had. I copperkoted it and was about to install before I remembered to check flatness. 0.004" is the limit and it was 0.015" or almost 4 times over. Head was not bent I could spin cam with fingers. Just heat puckered in the middle. When done could not get 0.002" feeler gauge under straight edge.

 

 

 

 

 

 

 

 

 

[Stoffregen Motorsports]

19 hours ago, datzenmike said:

 

Opened the rad cap then tightened it back on. Started the engine when cold. Gave a few sharp revs and shut off. Loosened rad cap slowly with ear near it and it hissed. Thought it was done so loosened it fully and it puffed out. Earlier I took the rad cap off and could smell gas and my sniffer is really old.

I bought a Willys wagon a couple years ago that had a "rebuilt" engine. I drove it once and in seconds it was boiling over. The rebuild consisted of new head bolts and paint. That's it...

[datzenmike]

Wednesday last I went over to islander's ' shop' and everything was ready to pull the head. He even made a wooden wedge per 510 manual specs. I ground it down slightly on the sidewalk so it would wedge better, god the worst of fates is to drop the tensioner and there is always a first time. Got the head off and expected to see it blown between 3 and 4 but nothing obvious. About this time we discovered that this is a Z22 block or an LZ22 we have. Nice! Has a Holly 2 bbl and the cam is reground. I took the head home with me preparing to sand it down if not level but after cleaning the surface the straight edge wouldn't allow a 0.0015" feeler gauge under it so I say it's good. Thursday we go to assemble an islander says 'how come the #4 piston top is so clean?' I said that usually a blown HG will let coolant in and it steam cleans it. Ding ding ding!!! We look at the old HG and sure enough there is a carbon track over the fire ring into the nearest coolant passage and that was the problem. Solved. Head goes on and torque it down in stages, cam sprocket fit like a hot damn and the wedge worked perfectly. So I go home and leave the rest to islander to put back together. He dropped by just this afternoon and said he had it running about an hour after I left. 

 

He dropped by this afternoon and took me for a ride and it goes crazy good. Compression on a Z22 with an open chamber L head is 9.89. Like I said Holly 2bbl 500cfm???, header, 63A 5 speed and 4:11 gears.  I have a spare cam that's reground and it still has a lip on the base circle and it's 0.480" lift. Islander's cam has no lip so probably around 0.5" lift? It goes very well. 

 

 

 

[banzai510(hainz)]

cool 510