Bubbles in radiator even after top overhaul..gurus help!

[mikoyreales]

help naman mga guru.. 1st time ko naexperience tong top overhaul. my ride is a second hand '97 toyota hilux surf (conversion). eto mga pinagawa sa oto:

- cylinder head resurfaced + hydrotest
- changed CH gasket
- changed valve guides, valve covers
- overhauled radiator (metal sya hindi plastic type)

1 week inabot yung trabaho. pagkuha ko ng oto sa mekaniko, ang sabi ok na daw. paguwe ko sa bahay, ok sya but after the 3rd day pag start ko e may makapal, mabaho at masakit sa mata na white smoke sa emission. pinatay ko makina then after a few minutes inistart ko ulit at hindi na sya naulit.

ang malaking disturbance saken e nagappear na nman yung small bubbles sa radiator! binalik ko sa mech at sabi normal lng daw yun sa makina ko.

question:
1) normal lang ba talaga na may bubbles ung radiator?
2) normal lang din ba na ung upper radiator hose ay napakatigas at mainit na feeling ko sasabog na sya?

pasensya na mga gurus, newbie lang...i hope you can lend some help.
TIA

[mazingerZ]

When you say bubbles - talaga bang parang boiling? Kasi kung me air pockets pa sa radiator at sa engine block normal lang kung maliit at hindi frequent. Did you try checking your dipstick - did your oil level decrease? Does the oil consistency have a milky texture (meaning parang mocca white)?

I believe na di pa nabebreak-in uli ang tsikot mo, try observing for say at least 500 kms, drive it moderately lang muna, until such a time na fully seated na ang components - say cylinder head gasket, oil seals, valves, etc.

[mikoyreales]

tnx sa reply! marami at frequent bubbles as in... walang changes sa oil level and consistency.

kgabi after 10 minutes ng idling, napatigas ng upper radiator hose. kabado ako baka mamaya magtodo bulging at sumabog, abutin pa ako sa hi-way. pressure build-up ba ito?

[speed unlimited]

Kung alam mong luma na iyong hose palitan mo na dahil din sa katagalan at init naapektuhan rin iyang radiator hose kung iyan ang inaalala mo para iwas abala kung bumigay hose mo.

[mazingerZ]

I believe so. Try replacing your rad cap to higher psi rating, and observe for a while.

[mikoyreales]

mga sir, normal ba na matigas at mainit ung upper hose ng rad?

[jvnj]

Sir Mikoyreales,

Can you give inputs on what parameters indicates in your temp gauge? Hindi ho ba sya mataas? Hindi ho ba nagbabawas ng tubig sa radiator?

Most likely, my guess are as follows:

1. Defective/damage CH gasket (probable illustrations by Sir mazingerZ)
2. Clogged radiator
3. Defective Thermostat (dont know the exact name, but its a mechanical device/part that controls the flow of radiator liquid)

Presence of bubbles in a cooling system is not normal. Also, kung di naman luma yung hoses nyo, di dapat sya tumitigas pag umaandar (as illustrated na parang sasabog), it indicates a high pressure system (might be abnormally high) which is a sign of restriction or abnormally high temp, dapat normal lang ang tigas. Better have it checked with a competent technician.

Thanks

[ARB]

does the water jump out of the radiator opening when the engine is on? try mo pa re torque ang cylinder head.

[miked]

does the water jump out of the radiator opening when the engine is on? try mo pa re torque ang cylinder head.

try "burping" your cooling system several times. open rad cap and let engine run with vehicle on an incline. front higher than the rear.

mine have continuous stream of bubbles...sometimes frothing.

right after starting, there is a considerable pressure buildup with the water still cold

sa mga hoses, better buy the OEM as well as clamps OEM din. upper hose is at a higher pressure (because of the action of the pump as well as water expands when heated) than the lower hose (sometimes vacuum occurs in the lower hose due to very high speed of the water pump = hose collapsing = overheating at highway speeds)

try retorquing your head bolts (when cold if aluminum head, while still hot if cast iron head) to specs if they are the reusable ones. do not retorque if they are the torque-to-yield bolts. head bolts torque usually in the 110-125 Nm range (about 80% of their shearing strengths)

just my info on this.

another DIY for me this weekend. the head gasket.

[mikoyreales]

tnx miked for that reply..cguro itry ko na lang iparetorque ung cyl head bolts.

i'll update you guys na lang next time. salamat sa mga inputs!

[mikoyreales]

dapat ba talaga lagyan ng shellac yung steel CH gasket? newly resurfaced kasi yung CH ko pero yun daw ang ginawa ng mech. sa pagbrowse ko kasi dito sa tsikot, nkita ko na dapat walang RTV kasi yun ang nagiging cause ng overheat kapag lumutong.

kindly enlighten me about this. maraming salamat

[bambino]

kung doubtful ka sa quality ng trabaho pwede ipa computerized cooling systems analysis ang oto mo . no guessing ang procedure na eto ,very accurate .

the question is meron kaya knowledgeable na shop dyan na pwede magperform ng ganitong diagnosis

[miked]

as per my experience and as per my own knowledge,

for a bimetal engine (cast iron block + aluminum cyl head), the alum cyl head expands and contracts more than the cast iron block.

since yun nga, expand and contract and so on naapektuhan ang clamping force ng bolt (lalo na kung yung reusable bolts i.e. hex bolts).

the torque-to-yield (i.e. 12-point bolts) bolts do not require retightening because they have the same clamping force at all temperatures therefore mas reliable.

RTV is not recommended for head gaskets. masyado malambot ito. it is usually used to absorb and contain oil-based fluids. not for compression purposes.

tingin ko sa shellac hindi sumasabay sa thermal cycling ng aluminum cyl head yung HG na may shellac as compared to a HG w/o shellac kasi napakatigas yung shellac eh. just do a wide reading sa internet, marami ka makukuha.

just my info on this.

[mikoyreales]

will retorque solve may pressure-build and bubbling issue?

no white smoke naman at no oil contamination as i've observed...

[miked]

will retorque solve may pressure-build and bubbling issue?

no white smoke naman at no oil contamination as i've observed...

masalimuot talaga ang troubleshooting....its like "shoot now, ask later"

it may solve the pressure buildup/bubbling....try retorque after 500 - 1,000 km.

if it will not solve the issue, baka matindi na warpage ng head or block or both at hindi na siguro chineck ng mekaniko...baka deretsahang replacement of part na lang ginawa without checking warpage....or worst case scenario, cracked ang head. wag naman sana.

just finished the disassembly, part cleaning and inspection....i used a straightedge and feeler gage to check warpage...salamat sa diyos at mas mababa ang nakita ko na warp kesa sa standard value...

[desert fox]

me crack ang cylinder head....

[desert fox]

o di kaya yung fan motor nya kailangan na papalitan.

nasabi na pala ni brotrekker13...

sorry...

+1 na lang ako....

[desert fox]

o di kaya sa silicone gasket na ginamit ng mekaniko...di lahat ng silicone gasket pwede sa Cylinder head....

nakupo baka backjob ito...

[miked]

Mine had bubbling and pressure build-up when cold issues....

kapapalit ko lang ng HG the other day on my 4D56B turbo engine with the federal mogul brand.

so far it runs fine as of today. no bubbling and pressure build up when cold...

i followed the instructions provided by mechanics here in tsikot plus the instructions on the manual plus advice/tips from my mechanics-friends.

i torqued to 3 stages (4-8-12 kgm) with 10 minutes settling time between the 2nd and 3rd stages....ang hirap pala magbasa ng manual torque wrench while torquing the bolts lalo na sa 3rd stage...how i wish na may automatic torque wrench ako na ginamit..napakamahal kasi nun

di na rin ako naglagay ng shellac sa HG...just the gasket alone.

once kasi na nagoverheat ang aluminum cylinder heads eh hindi na yan titino unlike cast iron heads...aluminums loose their original strengths drastically after 1 overheating only

[JayL]

Bro the fact that you are having some problems makes me think that the job might not have been done properly. Maybe it's better to get a second opinion now from a shop with the proper test equipment to diagnose a problem or certify that the engine is ok.

Last week we just did a valve job for a 1999 CRV that suffered a broken timing belt. In the process the Cylinder Head gasket was replaced too. No shellac or nothing to be placed , just the OEM gasket itself. None the less one has to have the proper torque data, steps and sequences to properly install the CH.
In this particular engine we cannot afford to do a re torque because we need to dismantle the timing belt and cams again in order to access the cylinder head bolts. It should be done right the first time or we're in trouble.







It's very important to get this part right for any engine or else the symptoms you mention can start popping out. I hope the bubbles in your radiator are just trapped air. If it's combustion gas then something is definitely wrong and the overheating you mention does not make me comfortable.

This is a tool that can used to verify if the escaping gas is indeed combustion gas.

[ame="http://www.amazon.com/gp/product/B000NPDL76/ref=ord_cart_shr?ie=UTF8&m=ATVPDKIKX0DER"]Amazon.com: UVIEW 560000 Combustion Leak Tester: Automotive[/ame]