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Need a reality check on head gaskets by pbf00t
Started on: 03-25-2014 01:51 PM
Replies: 24 (291 views)
Last post by: hnthomps on 03-26-2014 04:32 PM
pbf00t
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Report this Post03-25-2014 01:51 PM Click Here to See the Profile for pbf00tSend a Private Message to pbf00tEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hi All,

I have a 1987GT with pretty low mileage. The story is long so I'll hit the high points... when I purchased the car with 23k on the clock a couple years ago I noticed the radiator fan ran all the time and the temp gauge didn't work. I decided last summer to fix that. I replaced the three coolant sensors and in the process found the one-wire sensor to the fan had been shorted by the previous owner. Not good. I also had the coolant professionally flushed and followed all the instructions, checked the lines, etc. Even verified the water pump is working. Oil and anti-freeze are clean, at least to the naked eye and it is not leaking or burning either.

Soon as those sensors were replaced, the car started overheating (or started reporting it was overheating) and throwing code 14's. If I drive it with a scanner attached, the computer says the temp fluctuates between 270 and 280, just keeps going up and down between those two numbers.

I have the car at a shop in town and they have searched high and low for a problem, can't really find one, but they can confirm the car really is running that hot.

So, the idea on the table is that it must be the head gaskets - I'm starting to think based on the above and the fact this car has never done better than 15mpg that it has been overheating since I purchased it.

My Questions:

1. Are head gaskets a problem on the 2.8?

2. He wants to send the heads out to "have them checked for cracks and stuff" This make sense?

3. Says it is a 10 hour job, sound fair?

4. I have to do the AC compressor as well, I'm guessing this will make that job easier. Going to switch from Freon to R-whateve-it-is, is the 4-seasons 57255 the right compressor for this, I hear there a a couple different part numbers.

5. If we do this big a take-apart, is there something else that should be done at the same time? The car is 27k on it.

Thanks All
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Gall757
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Report this Post03-25-2014 02:02 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
From your description there is nothing to indicate that you have a head gasket problem. You have a water circulation problem. What is the temperature of your coolant in the radiator?
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84fiero123
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Report this Post03-25-2014 02:09 PM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
A candy thermometer is cheap at any department store. set it on the radiator or in it, but I think Gall is right, have you looked at the coolant tubes? if they are crushed that right there may be your problem, also you may have a defective thermostat, try running it without one. if that cools it down, that is most likely your problem.

Steve

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lou_dias
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Report this Post03-25-2014 02:21 PM Click Here to See the Profile for lou_diasClick Here to Email lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
confirmed the temp how?

When you replace the coolant temp sensor (CTS), did you use plumber's tape or some incompatible sealant?
The CTS grounds to the block so sealing it with something other than thread sealant/Permatex sealer may cause you to read too high (extra resistence raised voltage reading) or too low (no ground = no voltage).
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jaskispyder
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Report this Post03-25-2014 02:26 PM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Things to check...

bad radiator
crushed coolant pipe
collapsed/bad hose
thermostat
water pump (impeller slipping on shaft)
radiator cap


A shop should be able to pressure test the coolant system (or check for exhaust gases in coolant) and determine if the heads/gasket are bad.

How are they confirming it is running hot? Reading the sensor? The sensor could be bad, or the wrong one was used.

[This message has been edited by jaskispyder (edited 03-25-2014).]

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pbf00t
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Report this Post03-25-2014 02:37 PM Click Here to See the Profile for pbf00tSend a Private Message to pbf00tEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks for the quick feedback.

I'll try to answer all the questions.

He indicated they tested the coolant temp by the fill near the thermostat with one of those laser temp sensors... says the temp around that area was pretty much right around the reported coolant temp at that time. So it really is getting that hot. It overheats in less than 10 minutes just idling in park, in the winter.

I have run the car with and without the thermostat installed, I've also replaced it with a new one. Problem persists the same with, without and with new.

The CTS was installed with the same white stuff on the threads it came with out of the box new. No plumbers tape was added. Each mechanic I take it to installs a new sensor, I've probably been through four of them.

Coolant pipes are not crushed - checked that early on.

Hoses are all in good shape

Water pump impeller has been checked.

Radiator cap is new.

I'll look into having the coolant checked for exhaust gases.
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Report this Post03-25-2014 02:42 PM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Make sure the correct radiator cap was used.
http://www.fiero.nl/forum/A...110502-2-103304.html

My thought on this is that if you have proper coolant circulation, then you are not building pressure.

[This message has been edited by jaskispyder (edited 03-25-2014).]

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Gall757
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Report this Post03-25-2014 02:58 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pbf00t:
Water pump impeller has been checked.


That's not easy to do....Did you install a new water pump?

Just verify that your whole coolant system is hot when it is hot at the engine.
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Report this Post03-25-2014 03:01 PM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:


That's not easy to do....Did you install a new water pump?

Just verify that your whole coolant system is hot when it is hot at the engine.


That is my guess also. Unless they are checking volume and pressure, the impeller could be slipping under load. OEM will be fine, but if the previous owner replaced the water pump, it could have a plastic impeller. Not too many shops know about this I am guessing, as it seems to be an issue with older cars like the Fiero.
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pbf00t
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Report this Post03-25-2014 03:27 PM Click Here to See the Profile for pbf00tSend a Private Message to pbf00tEdit/Delete MessageReply w/QuoteDirect Link to This Post
I just checked with the mechanic on all the questions raised here.

They took the water pump off the car to check it.

The radiator is hot, not as hot as it is back at the engine, but hotter than it should be by quite a bit. So I suspect I have coolant flow.

The temps were checked at several points around the entire cooling system

The CTS is grounded properly

The correct type of radiator caps are on the car - there were some gripes about the radiator being lower than the engine coming from the shop.

No emissions checking in VT (the world capital for the Prius and we don't check emissions!!) so the way I understand it, not many shops are equipped to check the coolant for exhaust gases. At least not with the high-tech tools.

If it is not any of these things and not a head gasket or cracked head, what else could it possibly be?
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Report this Post03-25-2014 03:34 PM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would just ask them which cap they installed (or buy the correct one and install), and cross check that with my link, as I believe there was an issue that Stant had the wrong number in the lookup at one time.
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Report this Post03-25-2014 03:58 PM Click Here to See the Profile for pbf00tSend a Private Message to pbf00tEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jaskispyder:

I would just ask them which cap they installed (or buy the correct one and install), and cross check that with my link, as I believe there was an issue that Stant had the wrong number in the lookup at one time.



I'll go check the car. The car has been parked nose-down many times, if my overflow is not filling up is it safe to assume I have a non-vented cap? The same cap has been on there since this whole mess started almost a year ago.
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Gall757
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Report this Post03-25-2014 04:04 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Does your heater work?

Do you know the history of your car? With that low mileage it must have been sitting a long time unused.
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Report this Post03-25-2014 04:19 PM Click Here to See the Profile for pbf00tSend a Private Message to pbf00tEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

Does your heater work?

Do you know the history of your car? With that low mileage it must have been sitting a long time unused.


The heater literally works painfully well. As in so hot it hurts your hands on the steering wheel. I'm the third owner, I know the previous owner. it went from 18k to 23k between 1992 and 2010 while he owned it. What I'd really like to know is when the radiator fan was grounded and turned on all the time, that is probably when this problem started.
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Report this Post03-25-2014 04:29 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Perhaps you will need to back-flow the radiator to see how much coolant is getting through. If the car was stored with low coolant, half of the radiator could be plugged up. Will the fan turn on at 235*F now?
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Report this Post03-26-2014 11:22 AM Click Here to See the Profile for lou_diasClick Here to Email lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
May want to take a good look at the radiator and make sure there is no crud built up in the fins, lowering it's cooling efficiency...
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84fiero123
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Report this Post03-26-2014 11:45 AM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
I know this is a dumb question, but you haven't said since you fixed the fan, if it is coming on at the right temps or at all. is it?

because that is a rather important thing in these as it isn't supposed to come on until a high temp to begin with, 220 I think, isn't it guys?

but now I am leaning to that and a slipping water pump vain or pulley.

bad or leaking heads generally show exterior leaks or internal leaks, unless they are simply plugged water passages. external leaks are not always visible, but the residue can be, tell tail white residue.
internal would be muddy antifreeze in the radiator, under the radiator cap.

Steve

[This message has been edited by 84fiero123 (edited 03-26-2014).]

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Csjag
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Report this Post03-26-2014 12:01 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
Before they start taking off the heads I would want the radiator flow checked. A friend of mines Fiero was running very hot and he found out that the radiator was 3/4 plugged.
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Blacktree
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Report this Post03-26-2014 12:01 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
A bad head gasket can cause a lot of pressure to build up in the cooling system, because it's basically allowing the engine to pump compressed air into the coolant channels. But the cooling system already dissipates most of the heat generated by the engine. A little bit more shouldn't make a big difference.

Since you haven't mentioned excessive pressure buildup in the cooling system, I'm guessing you have a cooling system problem rather than a head gasket problem.

Also, just because coolant is flowing thru the system, it doesn't necessarily mean it's flowing enough. I'd be on the lookout for an internally collapsed hose, or gunked-up radiator.

Best of luck!

[This message has been edited by Blacktree (edited 03-26-2014).]

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Report this Post03-26-2014 12:11 PM Click Here to See the Profile for TriumphFetishClick Here to Email TriumphFetishSend a Private Message to TriumphFetishEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think I've seen test kits for hydrocarbons in the coolant at the O'Reilly's I shop at. I'd definitely look at the radiator before having the engine torn down like most have suggested.
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Report this Post03-26-2014 12:12 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
I agree with Blacktree. The ideal thing would be to take the radiator out and have a radiator shop check it instead of the general repair shop.
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Report this Post03-26-2014 02:04 PM Click Here to See the Profile for pbf00tSend a Private Message to pbf00tEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Csjag:

I agree with Blacktree. The ideal thing would be to take the radiator out and have a radiator shop check it instead of the general repair shop.


Well, I'm starting to like this mechanic more and more - I called to ask about the radiator and they already have it out of the car and are sending it out to be flow tested. The mechanic really does not want to pull the heads unless it really is the problem either.
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Report this Post03-26-2014 03:06 PM Click Here to See the Profile for TriumphFetishClick Here to Email TriumphFetishSend a Private Message to TriumphFetishEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wow! That sounds like a good Mechanic...
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Report this Post03-26-2014 03:35 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
sounds like an honest mechanic, good deal
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hnthomps
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Report this Post03-26-2014 04:32 PM Click Here to See the Profile for hnthompsClick Here to Email hnthompsSend a Private Message to hnthompsEdit/Delete MessageReply w/QuoteDirect Link to This Post
Is your coolant system properly burped? If not you can get some high temperatures indicated on your instrumentation. You may also want to cross check the computer temperature with the gauge to see if they are in reasonable agreement to see if the gauge temperature indicator is faulty.

Nelson
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