Probably need to replace cylinder head?

[Jedidiahwiebe]

Story goes like this: I was driving on one of if not the hottest days of last summer... up the highest pass on the I5 on my way to McCloud California... Heat on full blast, just to be safe, and watching my temp gauge like a HAWK because I was keeping pace with California traffic LIKE A BOSS... When wowzers the needle lifts into the red zone. I stop right away a km... and see that I have literally no coolant. Fill 'er up with my drinking water and drive bit more an hour or so later. When again, needle flies up, and this time I blew a heater core hose (only hoses that I didn't replace in my deli-tune. Tie 'er back on again. And begin the long limp home to BC. And I mean LOOOOOONNNG. Took something like 40 hours? Doing from 40km/hr to 90 at night when it was cold.
After this significant messup (ignoring all the warnings about driving slow on hot days re. cracking the head) I had literally only one symptom. Pressurised coolant. No white smoke, no blue smoke, no nothing odd. Heck I even got the best mileage of my delicareer (presumably due to the slow driving) The only symptom was that the coolant pressurised... Slowly if I kept the temp of the engine way down, and rapidly if i drove too fast or in to low of a gear. (Notably slower at night of course).

The insurance ran out about when I got home, so I parked it for the winter. Now it's repair time!

To recap. The only symptom is slight pressurisation of coolant. No smoke in exhaust, no coolant discolouration. Heck it even started first try after sitting all winter. (good guy delica!)

Glen told me last fall that without a doubt it's a cracked cylinder head. Between cyl 3 and 4

I'm inclined to believe him. All references to him on this forum indicate that he is The Titan of delica surgeons. And plus, I've met him. He seemed to really know what he was talking about.

Heck. I think i might just replace it with a new head, not even bother to test the old one for cracks. Save myself a the cost of having it tested!

Does anyone on this forum disagree with me?

Also, would anyone try and dissuade me from buying my new head from http://www.ebay.com/itm/120680775541?ss ... 1438.l2649 The phone number matches with a legitimate business http://www.mazdasparesuk.com/ Who seems to be reccommended by a couple members on http://www.mdocuk.co.uk/

Any thoughts? Words of warning before undertaking this job?

Thanks everyone for your Input!

[FalcoColumbarius]

When I first started reading your post I thought eww, crack by number three. Then you mentioned Glen saying between number three and four. He is truly a clever craftsman and generally a nice guy. I would be inclined to take his word for it. All the same, a decent 4D56T head is going to be in the neighbourhood of a G note when all is said and done so I would be inclined to find out for sure before purchasing said head.

Another point, what year is your engine? There are different models of 4D56 Cylinder heads, depending on the year. Also, is it a Japanese head? A Korean head? Taiwanese head? Mainland China head? I wouldn't just buy anything. I would be inclined to get the garage installing the head to supply the head.

Falco.

[jessef]

Glen told me last fall that without a doubt it's a cracked cylinder head.

His guess is the best guess out there. Before spending a dime on anything, have a shop do a compression and leak down test. Results will give you the green or red light to proceed.

Any thoughts? Words of warning before undertaking this job?

Yes. Have Glenn at Coombs, John at Radd Cruisers or Butch/Edwin at CVI do the head for you.

If you are asking the question, assumption is that you have not done a re&re on a head before but if there is no alternative and you are in the middle of delica-nowhereness, then depending on warping, the head (and block) will have to be machined prior to installing the new head/gasket. Use a Mitsubishi OEM headgasket and head bolts must be new as used ones have stretched past their torque rating. Download and printout the service manual in wiki.

[Jedidiahwiebe]

I intend to do the swap myself here... I have this mental block - that for some reason prevents me from letting other people work on my vehicle... probably more often than serves me any good. What can I say? I like engines?
I've never had the head off before, but I'm getting familiar with the engine, have done the timing belt and all seals myself, as well as had the fuel lines off various times. So... what surprises lay ahead other than the exhaust manifold/turbo? Can't be any harder than an engine rebuild? Yes? No?

I never considered the block warping. How can I check that? Will a .003'' tolerance straightedge do to check it?

I have come up on a rather upsetting short time budget, So my plan is to go ahead with the purchase of the new head, have it shipped over from the UK for half the price of getting one from any of the JDM importers in BC, and If I find out that the head was not cracked.. well then I guess I'll have a good used head for sale! Am I ridiculous?

Thanks for the tip about new bolts. I most certainly will!

[Jedidiahwiebe]

When you say 'compression and leak down test' do you refer to a procedure where i first remove the head, and then take it to a shop and they do some magical high pressure stuff on it?

Saving money is key here. My inherent trust in glen is causing me to just want to replace the head and see how it goes. i.e. skip the expensive 'take it to lordco for a 300 dollar pressure test'

I mean, it's pressurising the coolant without making a drop of white smoke, or discolouring the coolant. Plus tons of delicas crack their heads. Doesn't that mean that it is almost a garunteed crack? Not a gasket, nothing else? I suppose there is risk of the block being cracked, but I mean, i stopped pretty right away after the incident... I mean i was literally staring at the temperature needle just waiting for something bad to happen (and then it did!) So wouldn't it be more likely than anything that it was the head?

[thedjjack]

Since you like to do work yourself I would order a compression gauge and pre-test it yourself before you pull the head (just to see what the compression is in the cylinders (if you have good compression in 2 cylinders it will give you an idea of motor condition).

Then I would pull the head and inspect. Replace the timing belts, tensioners, water pump, and hoses when you are in there.

if you go slow and are careful the head is pretty easy to change. Pull both front seats and the front carpet and go to work.

I think there are 2 heads one with flush valves and one were the valves stick down (get the right one).

[Jedidiahwiebe]

Compression gauge! Great idea!

[jessef]

A compression (measures pressure) and leakdown (measures pressure loss) test is performed when cranking over the engine, so your Delica must be either at a shop or you have the tools to do the job yourself.

If both are within manufacture tolerances, then have the head inspected for cracks. Pressure and dye testing is the most common on alu heads.

If you go to the downloads/wiki, read through the service manual, it will answer most of your questions.

This forum is helpful but take it with a grain of salt. If someone says to do something and it's not correct or can cause problems for you, you have no recourse.

Here is a related example as both Claude's and your Delica exhibits similar problems - major coolant loss.

http://www.delica.ca/forum/loosing-coolant-12788.html

The difference is that his was leaking but the advice given to remedy his situation (using pepper in the coolant system) would have caused more problems in the long run.

In your case, having the compression/leakdown test done will give you the most assured direction to take instead of ordering a new head and dropping it on.

It would be beneficial to you to go through the service manual and do it right the first time and don't take any short cuts.

The difficulty in swapping a head is relative to the person's mechanical abilities and comfort zone.

Good luck.

[Jedidiahwiebe]

Update! So I pulled the head this afternoon and upon not being able to visibly identify any cracks nor anything that looked like a messed up area of the gasket itself I took it to the head rebuilding shop here in Salmon Arm. Andrew (whose claim to fame is 30 years experience) tells me that he can't see any cracks either, but he does see scratches. In his opinion the scratches are the cause of the problem. He tells me that I should have the head machined, and the valves seated and not to even bother pressure testing for cracks. (I told him to pressure-check it first thing in the morning anyways!)

Does it seem likely to any of you guys that an overheating incident would cause the head gasket to suddenly begin letting compression gas leak into the coolant ever so slightly? AND then during 1,500 km of subsequent driving NOT worsen at all? Doesn't this sound more like a crack to yous guys?

Also I didn't notice anything really off when i lifted the gasket. What does a gasket leak look like? Is it possible for a gasket leak to be small and not really visible?

Thanks!

[Jedidiahwiebe]

I guess what I'm primarily worried about at this juncture is that Andrew's pressure test will show a false negative. Is that possible? That there may be a small crack which the pressure test will not reveal, but after spending money to have the head machined, and new gasket and bolts I put it on and find that i still have a cracked head? In which case I'll have wished I just bought a new head?

Am I paranoid? Or is that a Possible scenario?

[jessef]

It is a possible scenario as the head is an unknown, especially of you're just going by a visual.

Did you do a compression test before you pulled the head?

[Jedidiahwiebe]

No compression test. Like you said about the grains of salt. I did mention it to Glen this morning and he said that it would be a waste of my time. I didn't see that it would be all that helpful either. I already know there is a leak somewhere. Compression test will only confirm that, but not help actually diagnose where the leak is coming from.

[legionnair]

If he is good he will find the cracks. Next time you could pick up a dye test from lordco/auto store and check for yourself. Its pretty basic just make sure its very clean. I have done alot of headgaskets which show the exact same symptoms as yours(most of these were big diesels) . What you look for is rusty streeks or black marks from the fire ring towards a coolant gallery.
For a quicker cheaper test before you remove the head take a rubber tipped blowgun and remove the glow plugs place the blow gun in the glow plug hole. Pressurize it with shop air and remove the rad cap look for bubbles or put a coolant pressure tester on and watch for pressure increase. Also great for quick testing for burnt valves and bad hole. Much cheaper to buy a $20 blow gun.

Something to chew on

Dustin

[thedjjack]

No compression test. Like you said about the grains of salt. I did mention it to Glen this morning and he said that it would be a waste of my time. I didn't see that it would be all that helpful either. I already know there is a leak somewhere. Compression test will only confirm that, but not help actually diagnose where the leak is coming from.

The only reason I said a compression test was to get an idea of the cylinder shape (no point in doing the head if you rings are getting bad (leak down test is better, but compression with oil works)). I like the "blow gun" approach (poor person leak down test)...

I think head gasket is most likely but having the head checked makes sense and should find the problems if any...On of my motorcycles when the head gasket was going out (air cooled 12:1) would start no problem on both cylinders but once warm expansion would result in compression into the oil passage and the loss of a cylinder...

an old injector gutted, pressure gauge, shut off valve and a compressor fitting is a basic leak down tester.

[Jedidiahwiebe]

Good point Thedjjack, but I am pretty confident in the condition of my engine. I suppose i could have done a compression test just to know, but the engine has been performing very well, so I wasn't worried about rings.

And Dustin: Thanks for your tips! Cool information to know and chew on. Very resourceful!