[Rob]

Well, this past sat. started out as a good day, i got my gt back from the shop, and i hadnt been driving it for ten minutes when this guy stops me at the gas station and tells me how good he thought my car was. So i go back to the shop to tell my mechanic how it drove and pick up my dad to take him for a ride. So we are cruisin down the road gettin envious looks from people in jags and the like. After hitting some stop and go traffic, i noticed some white smoke coming out of the hood vents, so i looked at the temp guage and low and behold, it was up on the last white tick mark. We pulled over to see what the prob was and it immediatly stopped after we pulled over to let it cool, but we limped it back to the mechanic anyway. He looked at it, determined that the water was low, and the rad. cap was loose, so he fixed that and we all went to lunch. After we got back, we flushed the radiator and water jacket and some pretty gross looking rust and "mud" looking stuff came out, so we thought that it ws fixed and i drive it home.
Roughly 25 min later i got on I-985 to go home and i noticed that it was running pretty hot, so i backed off the go pedal and just cruised along about 60-65. Well, a minute or 2 later, the thing had overheated again, so i pulled off to the side and topped off the radiator and let it cool down some before i set off again. Anyhow it overheated about 2 or 3 more time before i got home, so i let i cool and then on sunday i flushed the radiator and jacket again. for about 25 min after that, it ran well and not to hot, so i thought i had fixed it. Not so, i had to drive to a church function, and it was only about a 10-15 mmin drive, so i decided to take the gt and wow all my friends at church. it does fine on the way over and then at about 10 pm, as im driving home, it starts to run hot again... basically my question is: do i need to try flushing it again even though no crap came out the last 2 times, or should i take it to the mechanic's and let him pull the head and manually clean the jacket? The radiator is new, so i dont think thats the prob, but when it was replaced, we found a lot of "radiator leak stop" stuff in it, so i think the water jacket might have severly resticted airflow. Also, my car doesnt have the radiator-fan shroud thing, is that very important, and if so, where can i get one?

 

[jlthunder]

I ran my radiator without the shroud for many years, so I don't think this is the problem. I did see one on e-bay the other day so it couldn't hurt to get one.

What temp is your thermostat? I'm running a 170 with a new radiator and it stays just below the middle temp range. What year is your GT? Be very careful if you have the extra 2 nuts at the front of the head. High temps will crack valves on these heads(common on late 72 and 73 GTs & 74 Mantas and Asconas)

Since you found a lot of "leak stop" in your old radiator, it might be in your block. I would remove the radiator, back flush it so it doesn't destroy your new radiator. Remove the thermostat and water pump and take a look at the water jacket. You can get a new water pump gasket from OGTS. If it is covered in the "leak stop" talk to your local mechanic to see if there is a way to flush it out of the water jacket.

Just my 0.02

 

[greensmurf20]

i used to have the same problem and it didnt go away until i rebuilt it to a 2.0. i used the same thermostat housing and thermostat on it and it ran COOL. so i'd probably think its the waterjackets have a bunch of crap, or flow is somehow restricted somewhere.

 

[madhatterpdc]

I would also check the cam and ignition timings. I replaced the timing chain on an old Honda I had and was a tooth off. The engine ran VERY hot after that but wouldn't make any power. I moved the chain, and it ran great (as well as it did before I "fixed" it )

 

[baz]

if its been flushed you may have a blocked thermostat
(all that crud can jam them) take it out and hang it in a pan of boiling water and see if it opens if not then replace it and you're good to go
if it dose open check to see if your water pump is working ( 2 easy ways) first start car with rad cap of and see if you can see any water movment
second dose the heater work good and hot as this needs a good flow from the pump to work it
if no joy then you must have trouble in the block or head
and as said earlier in the answers these engines just do not like to be run hot even if it means letting it cool then drive till it runs almost hot and stopping to cool it again
one other tip NEVER PUT COLD WATER IN A HOT CAR it will cause cracks in the engine because of the temp change this is cast iron we are talking about

 

[bear]

Here's a thing I did on my V-6 before I tried to start it on the stand. I got a submersible pond water pump, got PVC plastic fittings to mate it up with my radiator hoses on the engine, dropped the pump in a 5 gallon bucket full of water, plugged it in to an AC outlet and let it run. After the water level in the bucket stabilized, I put a pint of radiator flush in the bucket and let it run for 12 hours. This was with the thermostat out of course. After 12 hours running, I dumped the busket and cycled fresh water into the bucket and let it run for another 12 hours. Then flushed the whole system with clean water. After I was done, there was nothing but cold clean water coming out of the engine. Main reason I did this was to make sure the cooling system was not gunked up. Most radiator flushes will not do the job if you read the instructions on the cans, unless they contain some type of acid and will need a neutralizer. The standard over the counter radiator flush needs no neutralizer and can be cycled as I did for a long time to clean out the gunk in the water passages.

HTH.

Ron

 

[madhatterpdc]

Namba,



When I first read your post I thought you were recommending the engine to run on the stand for 12 hours at a time. Common sense kicked in and I realized that you were talking about letting the submersible pump run for 12 hours and allowing the water to flow through. Makes a lot more sense that way

 

[bear]

Yeah, that's what I meant, I guess I'll have to be more explicite so no guess work is needed. I used the same system when I ran the engine on the stand and it worked perfectly. Now when I need to flush any of my cars, I use the same setup, just different adapters to the radiator hoses.

Ron

 

[madhatterpdc]

...I guess I'll have to be more explicite so no guess work is needed...

I think I need to pay attention more, your words were clear.

 

[Jeff Pozorski]

"Roughly 25 min later i got on I-985 to go home and i noticed that it was running pretty hot, so i backed off the go pedal and just cruised along about 60-65. Well, a minute or 2 later, the thing had overheated again, so i pulled off to the side and topped off the radiator and let it cool down some before i set off again."

Nobody has mentioned that you have to keep topping off the radiator when it overheats. Is the radiator cap relieving the pressure and blowing off the coolant? If not, you have a leak somewhere that is allowing enough coolant to escape that the engine overheats due to low coolant. Is your exhaust white or smelling sweet? Though a head gasket leak that bad would probably leave a huge plume of steam behind you. Check the lower radiator hose fittings that they are tight. When the rubber hose swells under the heat of the coolant it may allow leaking to happen, if the clamp is n't good and tight, either at the engine or radiator that is not readily noticible at highway speeds.
Good luck and let us know what you find out.

 

[oldopelguy]

bubbles

One unfortunately all too common issue with out old Opels is a crack in the head allowing exhaust to get into the cooling system, at the same time putting it under too much pressure and displacing all the coolant. It is compounded on the GT by the fill ear on the radiator which won't allow the gasses to escape the cooling system.

To check for this, fill the radiator to just visible in the filler ear on the radiator and start the car. Normally the level surges down slightly and then back up slowly as the engine warms up. I bet yours surges up and out right away and continues to bubble as the motor runs. If the results are inconclusive, take the car to a good radiator shop and ask them to test for exhaust in the coolant. They have a litmus paper like stuff that gives it away immediatly.

Any overheating of an Opel should be avoided, most importantly in the newer motors with the 2 additional bolts in the front of the head. While not terminal, the head will have to be replaced as there is no way to fix the problem. Good luck!

 

[Rob]

Well, i have a 1970 gt and i dont believe anything is wrong with the head gasget. The exaust isnt sweet smelling or white...but i havent checked for bubbles in the antifreeze filler nozzle.

On another note, i have found that there's a prob in my electrical system somewhere. Every time I try to start the car, I have to jump it off. The alternator works well, pushing about 7 amps at idle and the battery seems to not be dead, so, Ive concluded that there's a short, but i dont know where.

Thanks for all your help so far, and please keep it comin'!

-Rob

 

[bear]

O.K. let's go to problem #2, when you turn the key to the start position, does the solenoid engage or not. Does the engine rotate slowly if the solenoid engages, and appear to be a bad battery. Inquiring minds need a more descriptive commentary on the problem.

Ron

 

[baz]

ok rob lets start form the begining
1: why was it in the shop in the first place was it temp related? had the mechanic pulled the rad hose or thermostat or head
could he have put the thermostat in the wrong way aroung which stops it working
2: when you run the engine dose the top hose go very hard (this
means pressure in the water from a blown head gasket or a cracked head by a valve as OOG said
3: did you look to see if the pump was working yet? easy way is to feel for heat from the heater
4: try removing a spark pulg and crank the engine to see if you get a spurt of waterthrough the plug hole as the crank problem could be water in a cylinders (from a crack or shot h- gasket)
do this one at a time
5: try charging the battery to see if it takes power as it could just be flat (it takes about 15 min of driving to put the power back that starting a car takes)
if it was a short and a full charged battery was flat in a short while then you would find the short by looking at a nice fire in the harness (200 odd amphours are enough to wild steel with never mind fry wires)
that should do for now

 

[Rob]

Well, where do i start?

I bought the car in late August and never knew what i was getting into. At first glance, we knew the brakes werent working and the engine hadnt been run in over 7 yrs. As things started getting fixed, new problems began to arise. The worst of these was the cooling system. It seems that the previous owner found a hole in the upper thermostat housing about 1/2" in diameter and tried to fix it with "radiator leak stop" needless to say, i had to buy a new radiator core and then m y mechanic started looking for stuff cought up in the water jacket. He cleaned it out several times and thought it was good, but it obviously isnt.

The solenoid clicks when i try to start it but it doesnt turn over. I tried jumping it from 2 points, the battery and a combination of the starter and the frame. It starts much quicker from the frame/starter point. I assume this means either a bad battery or a bad batt connection.

-Rob

 

[Rob]

Also, does anyone know where to get a choke housing for a solex? If the car dies(which happens pretty regularly if I let it idle for more than about 3 sec) it wont start again, as i have said before. This gets pretty old during driving, as i am used to downshifting and holding the clutch disengaged. Anyhow, ogts doesnt seem to carry them and i need one pretty badly, so any help would be appreciated.

Thanks again,
-Rob

 

[nobody]

Just an idea on the starting issue. Look to see if the original ground strap to the battery is being used, they are pretty famous for coroding and giving a bad ground or the strap from the block to the frame rail.

 

[kwilford]

Two thoughts come to mind. First, look for a bad ground strap connection between the engine and the chassis. It's on the passenger side, from the frame rail to the lower part of the engine block just above the oil pan. I suffered through this fault for about six months (many years ago). I became proficient at parking on hills so that it would "roll start". In my case it was just a loose bolt where the strap connected to the frame rail. And it ran perfectly once started.

Well, it did once I trashed the Solex. Which I suggest you do as well. Get a Weber. Period. Full stop. Don't waste your time trying to get the Solex to work. It will NEVER function properly once it begins to do the things it is doing. A used Weber can be had for a small amount off eBay, or ask around this site and many members have used, rebuild-able spares that will work wonders for your GT

Also check the battery ground strap, and the connections at the solenoid (on top of the starter). It might also be a a bad ignition switch (a VERY common problem on GT's), which can often be overcome by installing a relay activated by the ignition switch, and the relay then provides the "Switch" that powers the solenoid. Search for "Otto-Start". But if the ignition switch points are too badly burned, you either have to re-build the switch (a nasty job), get it rebuilt by OGTS (a bit expensive), or install an aftermarket switch of some sort (either a full aftermarket keyed switch or a "push to start" switch, like on a Honda S2000, or really old British cars!).

As for the cooling problem, that concerns me a bit. Overheating can spell death to Opel CIH heads. Routine overheating is usually often related to a stuck or plugged thermostat, or a badly worn water pump (although they usually leak before they fail to pump coolant), but seldom due to plugged block coolant passages. Plugged radiators are more common, but you say yours is new. Tough thing to trouble shoot over the Internet.

And before the Moderator Police hunt you down, ask one question per thread and start it under the correct heading

 

[Jeff Pozorski]

Regarding the overheating have you tried replacing the thermostat? There has been much discussion on some Opel sites that the quality of some new thermostats is highly suspect. Some owners have had to buy 2-3 thermostats to get one that works properly. This could explain why the problem seems to be intermittent rather than immediately. Try the boiling test to make sure the thermostat is working. Do a search of this site for the best brand to use for the Opel engines.

Almost forgot: use the shroud!! It makes a huge difference in the amount of air flow passing through the radiator and past the engine.

 

[baz]

rob has the stalling only started since the overheating? and you dont say where you are from to know your tuning needs
so this is going to be guess work but here we go

if the car allways stalled then you need to set up the carb first warm up the engine to normal temp
screw the idle air adjusting screw all the way in then adjust the throttle stop untill you have 700-750 rpm
now turn out the idle air screw till you get 850 rpm
that will allow you to drive when you fix the over heating
if you can not get a choke cover then why not put a cable choke on so you only use it to start when cold


PS what kind of mechanic did you take it to as this is very basic stuff thay should have done in the first place