Head gasket installation need help!!!

C

cchris

Member
-2002 mazda protege5, stock
-overheating when running for more than 15 minutes on the freeway
-coolant in the coolant reservoir depleted unusually fast and there was back pressure that caused bubbling in the reservoir
-engine bogging, probably due to coolant/water in the cylinders
-the water pump was recently checked by a mechanic and it was okay

because of those symptoms the head gasket was replaced. installed a new Fel-Pro head gasket (https://www.napaonline.com/Search/Detail.aspx?A=FPG26194PT_0238844833&An=599001+102002+50042+2042052) and used Hi-Temp Red RTV Silicone Gasket Maker. A very, very thin layer of the RTV silicone was used. New head bolts were also used.

The head was milled and checked for warping by a machine shop. There was no warping, however, I don't know how much milling was done on the head.

The head bolts were tighten according to specs. Assembly was based on 2002 mazda protege workshop manual (http://web.archive.org/web/20050311003549/protege5.ugly.net/). When attaching the intake manifold back to the head, the gasket may have shifted a little. The intake manifold had to fit over two undetachable bolts that were connected to the head so the head was shifted around until it would fit. I figured that putting the head bolts in would have shifted the gasket properly back in place (any recommendations on this step?). The timing belt was professionally done and the tensioner was replaced. After the engine was fully rebuilt, it started nicely and idled around 1100rpm. After the engine warmed up the idle was rough and the rpm fluctuated between 600-1000. Also, there was water coming out of the tail pipe.

compression test was done and the results:
cylinders 1 and 3- 120
cylinders 2 and 4- 150

I thought that the head bolts might not have been tight enough since the head was milled and not compensated for. An extra 45 degrees of tightening was applied. After reassembly, engine still idled rough.

I also read somewhere online that RTV silicone can be dissolved by gasoline. However, a very very thin layer was used on the head gasket and extra tightening was applied.

Now what?
 
You need to put a new headgasket in. Rtv should never be used on head gaskets. The head and block should've been completely clean of any material and oil or other residues. There is a product called copper coat that is made for headgaskets but not needed. . The sealant you used could end up in the cyl's and or valves. Only fix will be taking it apart and starting over. And don't forget to check your bolts for stretching especially after your additional 45 degrees you mentioned.
 
White_2002.5 said:
You need to put a new headgasket in. Rtv should never be used on head gaskets. The head and block should've been completely clean of any material and oil or other residues. There is a product called copper coat that is made for headgaskets but not needed. . The sealant you used could end up in the cyl's and or valves. Only fix will be taking it apart and starting over. And don't forget to check your bolts for stretching especially after your additional 45 degrees you mentioned.
Click to expand...

the FS uses torque to yield bolts, they are usable(or should be used) only once. Multiple uses risks the bolt snapping in the block.
 
Yes. I couldn't remember the name besides stretch bolts. And im also writing this from my phone. So more difficult to review.

But don't forget to have a leakdown done of the head to ensure you didn't coat the valves and make them leak. Thanks
 
I had similar symptoms, leak down test showed it was a head gasket. Had it replaced and it's all g
 
tear it down as posted above... clean everything, get new bolts... DONT use RTV on the head.. just put it togather and check the timing and everything while it was there
 
as far as compression is concerned... 120 is LOW.... when i rebuilt my block i was worried ab out being 170 ineach or more.... 125 is the lowest spec ( i am pretty sure that is what omitchelle on demand said when i loked) 125- 190 for stock specs.. having them in a close range to each other is good
 
I just replaced my clutch, all motor mounts and headgasket. I had 185psi across all 4 when I was done. Had 185 175 150 and 180 before due to a blown headgasket. I have around 250miles on it with no problems yet. No sealant required. New head bolts and other gaskets where parts were removed.
Good luck.
 
where are you guys getting the head bolts? Are you paying the $12 each that the dealer told me they cost? That's the only place I can find them.
 
Do any of you torque the bolts higher than the shop manual has them listed? When I did this the last time I torqued them to dead center of the recommended torques. When I went to take stuff off to get to the head gasket I found some of the bolts so loose I could take them off with my fingers.
 
therris said:
Do any of you torque the bolts higher than the shop manual has them listed? When I did this the last time I torqued them to dead center of the recommended torques. When I went to take stuff off to get to the head gasket I found some of the bolts so loose I could take them off with my fingers.
Click to expand...

I don't understand your statement. Did you have to redo the head gasket or something? I always torque to the upper end of the spec, but never over. There's a reason they have an upper torque limit.
 
And after torquing all the bolts in the pattern. Check it again. If you find loose ones - then you will check all again until a whole run around the head yields no more tightening needed (all pass a torque test).
 
therris said:
Do any of you torque the bolts higher than the shop manual has them listed? When I did this the last time I torqued them to dead center of the recommended torques. When I went to take stuff off to get to the head gasket I found some of the bolts so loose I could take them off with my fingers.
Click to expand...

The shop manual lists a torque setting of 13.5 to 16.5 ft.lbf in step 2 of the cylinder installation. When you say you torqued to the center of the torque figures, are these the figures you used and did you stop at that point? If that is all you did some head bolts may not be more than hand tight.

You have to perform steps 3, 4 and 5 to complete the head bolt stretching.
In step 3 a mark is painted on each bolt head. In step 4, using the mark as a reference turn the bolts an additional 85-95 degrees in the sequence shown. In step 5 you tighten the bolts another 85-95 degrees. A torque wrench isn't needed for these steps. The complete procedure is required to get the correct bolt stretch.


Clifton
 
Last edited:
So I rebuilt the head again, but this time used copper sealant for the head gasket. The head and block were cleaned with carb cleaner prior to assembly. The block was checked and there were no cracks or signs of distress. The engine started fine and idled nicely, however, after completely warming up the idle became rough and the engine slowly died. The timing was checked- all marks lined up and the engine ran smoothly at high RPM. Water was coming out of the exhaust at high RPM again.

I'm confused. The only thing that could allow water to come out of the exhaust is a bad head gasket, warped head, or warped block, right?

I'm going to do a compression test and a leak-down test.
 
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