To check the head gasket --- your repair shop could remove the radiator cap and place a 4 channel gas analyzer - used to check emissions at the rear tailpipe - near the radiator fluid top tank inlet. The sniffer part of the emissions gas analyzer will pick up any trace of exhaust fumes that may be present in the coolant flowing into the radiator. This is the most reliable test to determine the presence of exhaust in the cooling system - which is the main culprit with a blown head gasket.

You should also look for any trace of coolant near the vicinity of the water pump housing. Water pumps were an issue in the 2007 Sx4s and there may have been a TSB --- if not water pumps were covered for 100K powertrain warranty period.

I had to replace my water pump at 42K when symptoms like you describe showed on my car ---- that was 4 years ago and no problems whatsoever since that repair.
This is NOT a cheap repair as a lot of components block access to the water pump housing. Use only the factory Suzuki water pump if you replace.

Also have you power flushed the cooling system? Also if you are adding coolant regularly that means that the coolant level is going down and that fluid is going somewhere. Have you checked your oil lately to determine the presence of coolant?

 

Are you basing this theory of intermittent overheating solely on the behavior of the temperature gauge or has there been some other symptom - boiling over perhaps - you mention periodically topping up the coolant - how often do you have to do this, and how much coolant are you adding?

The reason I ask this question is that different people define overheating differently, and some of the symptoms they define as overheating can and frequently do have other causes.

The need for periodic topping up indicates a leak of some sort - which could be caused by overheating and if not topped up in a timely fashion could also be the cause of overheating.

Spikes in the temperature gauge reading may or may not be an actual overheating condition - if that is the cause of your concern I would suggest you try to get an OBDII reader (a scangauge or similar) and see if that displays similar spikes in the coolant temperature.

Also important - how rapidly do the changes in temperature occur - it takes a considerable transfer of energy to cause temperatures to change rapidly, so if you're looking at the gauge climbing rapidly and falling rapidly - it MAY not be an actual change in temperature, but possibly an erroneous or erratic gauge reading.

 

intermittent over heating

Thank you both for your help - I really really appreciate both your input. This morning, we checked the coolant level and put more in. The new radiator cap was put on, as in the past, this seemed to solve the problem. The gauge went into the red on my way into work. At lunch, I checked it and put some more in. When I got home, the overflow was high and looked like it was boiling. I could smell coolant.

When it starts to run warm, we have replaced the cap. Now this may be a different issue? Hard to pinpoint, since it has been sporadic. We haven't had to add more coolant since the last cap change (month ago). My husband is also heading towards thinking the waterpump based on both your input. The waterpump is hidden so well, we can't visually see anything. And so well hidden, it must cost bucks to replace. I guess i'm off to the garage (again) this weekend - will have the headgasket test and ask him to look at the waterpump. How bad will replacing the waterpump be? I've already put $ into this vehicle - and i don't have alot to spare.

 

intermittant over heating

ok i brought this to my garage to have them check this out and they could not find any other possible cause except to replace the radiator cap, which they did. They did the test for the head gasket, which came back negative, replaced the radiator cap and drove it around. temp did not spike. They also checked the hoses.

This morning the temp spiked 3 x's on way to work. Rose and came back down in a short time frame. When I got to work, i saw the overflow was full and boiling. I also smelled coolant.

I had the thermostat changed in May and they are tending to guess this may be a defective one. Is that possible to cause these symptoms? I asked about the water pump and blockage in radiator and they said it is most likely not those issues as they would not be intermittant. any guesses? it only seems so far to happen on long highway drives, at sporadic times and not local driving, so i guess it would not be the fan. i doubt i had 4 defective radiator caps - my chances of winning the lottery would be better. help pleease?

 

ps they did tighten up one hose with a clamp and this may have accounted for prior needing to top off the coolant. it was a small escape of fluid, nothing major.

 

If you have not replaced the coolant according to the factory maintenance schedule, the radiator may be getting clogged with goo.

A power-flush would probably be a good thing to do, after a cooling system cleaner was introduced into the system and run for a while.

If the radiator is too full of goo, to be cleaned out by a power flush and fill, then the radiator may have to be replaced. I had to do that on a Ford LTD, years ago.

Good Luck,
Shadow

 

over heating

Thanks for all your help - we are tending to think it may be radiator/fan problems and are going to change those out to see if the problem is resolved. (a 2nd new thermostat didn't correct the problem).

Is it advisable to change the relay for the fan to radiator at same time? Where is that relay located?

 

What you describe does look like a head gasket problem..a car as recent as yours....2007 is not that old...rarely fries the radiator and playing with radiator caps and thermostats is equivalent to a prayer...yes one hopes this would solve the problem..the other options being undesirable
..one more symptom to confirm exhaust intrusion in the cooling system (blown head gasket) other than gas analysis as suggested...would be intermittent heat coming from the heater....that is, you ask for heat and sometimes it gets warm, then cold....etc.

what you did not say is car mileage .....

 

intermittant over heating

Hi LMP - thanks for your help. the mileage is 163,000. Yes, the thermostats and caps were a prayer.. and sadly no improvement. the heat and air both work fine (no cooling or heating problems). I called a Suzuki service place and the mgr asked me if there was any smoke out the exhause (no) or running lousy (no). I think he was leaning towards a radiator/fan problem - hope this is it as I think a head gasket repair will be around $1,500. To replace the radiator and fan (us doing that) will run around $300 so we will probably start there. He seemed to rule out a water pump issue as either they tend to work or don't. Its only a problem under heavy load/acceleration. A previous car I had (Geo Tracker - same engine I believe as this SX4), had needed a head gasket repair and it ran hot constantly.. I'm crossing my fingers with this repair.. Thank you again

 

I'd probably save the $300 and apply it to the head gasket by having a thorough test for exhaust from the radiator. SImply remove the radiator cap....fill it to the top if not, and run the engine. A blown gasket will pop exhaust bubbles from the radiator, specially when throttling the engine; have someone engage in drive (for an AUTO) while holding the brakes and torque the engine a little with throttle: you watch for the radiator "exhaust"....FOR a manual transmission , even without throttling (you would need 3 feet...) , there might be significant exhaust from the radiator.

Meaningul "smoke" from the exhaust pipe is not always present even with a gasket leak....except if a serious amount of coolant invades a cylinder at rest and then is expulsed in the exhaust system at startup. My late DOdge Omni kept blowing head gaskets and never made it visible at the exhaust....

 

intermittant over heating

OK - have the new radiator and fan and trying to get the old ones out. Have removed all nuts (holding on the front bumper cover) except for 2 that are inside the wheel well.

What size nuts are these? should be 10 millimeter but they are not coming off and i am afraid of stripping them. Is there a trick to removing these? Am trying to get the bumper cover off in order to access the radiator. Should not be this difficult... Anyone ever seen this - must be something we are missing! Thanks again...

 

OK - have the new radiator and fan and trying to get the old ones out. Have removed all nuts (holding on the front bumper cover) except for 2 that are inside the wheel well.

What size nuts are these? should be 10 millimeter but they are not coming off and i am afraid of stripping them. Is there a trick to removing these? Am trying to get the bumper cover off in order to access the radiator. Should not be this difficult... Anyone ever seen this - must be something we are missing! Thanks again...

Below are the instructions to take off the front bumper. There is only a phillips head screw and plastic clip that you remove with a flathead screwdriver in each fender to get the front bumper off.

How To: Remove Front Bumper / Install SS Cooling Ventilator

 

intermittant over heating

Shultzey - Thank you!! That did the trick! Got the bumper cover off, have changed out the radiator. Next problem is the cooling fan. I have an automatic vehicle. I ordered a fan from an aftermarket - and it came as a 2 pin plug. I need a 4 pin plug. The only difference is think is manual vs automatic. Where can i get a relatively inexpensive 4 pin plug - cooling fan? Suzuki wants around $400. The only ones i see online anywhere are 2 pin. Any idea?? Even for a gently used one?

 

I have one I can sell you. PM me to make an offer and discuss details.

 

intermittent overheating under load

p.s. it was the head gasket. actually the gasket was in tact (apparently has some flex to it), however the head was warped and needed machining.. all fixed now and doesn't overheat.

however it now drinks oil...around a quart every 3-400 miles. no leak detected - no exhaust smoke. any ideas now? runs beautifully besides that 'little' fact..

 

If it's not leaking it, it's burning it - start with wet & dry compression tests, that will give you some idea of the condition of the engine, but it may be time for a replacement.

 

Thank you all for the 2007 SX4 information

There are many that never post, like me, but read all of the posts from all of the helpful posters with great information! So Thank You!

 

I really thought it was gonna end up being water pump.I had the same exact symtoms you described.Just with my ford ranger and it was the w pump

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