YUMADTHO

So ive read numerous threads on this but not all of my symptoms are fitting with the other threads.

Backround: I bought this truck with the owner telling me and showing me of pictures of the "headgasket replacement" he just did. I drove the truck for about a week and all of a sudden i had the high idle and surging idle when on breaks symptoms. checked vacuum and cleaned coolant lines going through the throttle body.

While trying to fix the above problems the truck started building pressure in the radiator and pushing coolant out the over flow and leading to overheating issues. I opened the cap and it looked like a jacuzzi tub inside so i replaced water pump, thermostat, radiator and coolant lines. This solved my building pressure issue but its now burning coolant and running warm after it burns coolant until it has about half and gets hot. I checked compression and its #1-180 #2-150 #3 151 #4-150.
So im at a loss. The previous owner replaced timing chain guides but not sure if they might have worn through the cover and getting coolant through there? Also thinking the obvious headgasket but makes me double think because of somewhat good compression? Thanks i am very open to suggestions on this!

Kiroshu

Burning coolant...? Meaning its entering the combustion chamber...? Or are you just generally leaking coolant...?

Check engine oil quality...? Coolant leaking/mixing into oil...? "Milky" color engine oil...?

Compression readings don't seem unusual except for cyl #1 being higher than the rest.... usually its the opposite... wear cylinder one is usually slight lower due the water pump jetting cold coolant directly on cylinder one.... being the nature of the engine and all.

Maybe re-check compression. Warm up engine to operating temperature and re-perform compression test.

YUMADTHO

I say burning because the previous owner also cut the muffler off about 2' after the cat and i could see wetness on the rear axle and its smells like coolant somewhat. there is also milky oil and high oil right after oil change. and when i say going through coolant i mean about 3/4 of a gallon in about 30 miles. Very bad, the overheating is due to when it burns/uses so much coolant that it doesnt have enough to keep it cool until then it runs at about 1/3 on the temp gauge.

dswag

I would say that the PO of your truck fed you a line about him just changing the headgasket, either that or they had no clue what they were doing. Sounds to me like you've got a blown headgasket, milky oil and your oil level being high when changing. Sorry about your luck man, atleast now if you fix everything you'll know it was actually done...... and the right way at that.

Kiroshu

^---x2

Yup either the head gasket repair(s) were never performed and or performed incorrectly....?

Also possible timing cover damaged internally from timing chain component failure. Timing chain rubbed a hole in water passage in timing cover.

If compression readings are indeed correct I would lean more toward the damaged(leaking) timing cover.

Sounds like you got to take it apart and see what's going on.

Good luck. I would not continue to run the engine in this condition as further damage may result.

dswag

Ya #1 cylinders compression is ridiculous compared to the other 3. I'm thinking that Kiroshu is right by saying that your problems could be coming from a possibly damaged timing cover.

Nailit69

Other than possibly leaking water into the oil, what would the timing cover have to do with the 180psi compression reading? It's just a cover that happens to house the water pump, it has nothing to do with the compression. 180psi is about where a new engine would be and they should be closer than that, within like 5 lbs.

For an accurate reading you should remove all the spark plugs and re-check your compression. I've gotten some erratic readings before by not having them all out when you do the check.

I would also check/re-torque the head before you do the test and while you're at it check everything else, sounds like some clown did the work and probably used the wrong tools.

As for the surging, i've experienced this before and it was something to do with the cold start solenoid or something like that. I've also had to punch a hole my headgasket before because it was improperly/not punched during manufacturing, make sure all your waterjacket holes are punched in it (if you take it apart).